<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      color: #1e2945;
      background: transparent;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px;
      gap: 12px;
      user-select: none;
    }

    /* SVG Triangle visual */
    .triangle-container {
      width: 100%;
      max-width: 420px;
      height: 150px;
      display: flex;
      justify-content: center;
      align-items: center;
    }

    svg {
      width: 100%;
      height: 100%;
      overflow: visible;
    }

    .side-line {
      stroke-width: 4;
      stroke-linecap: round;
      transition: stroke 0.25s ease, stroke-width 0.25s ease;
    }

    .side-label {
      font-size: 13px;
      font-weight: 700;
      transition: fill 0.25s ease, transform 0.25s ease;
      text-anchor: middle;
      dominant-baseline: central;
    }

    .angle-arc {
      fill: none;
      stroke: #64748b;
      stroke-width: 2;
    }

    .angle-label {
      font-size: 14px;
      font-weight: 700;
      fill: #475569;
    }

    /* Cards Layout */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 10px;
      width: 100%;
      max-width: 600px;
    }

    .ratio-card {
      background: #ffffff;
      border-radius: 12px;
      padding: 12px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      cursor: pointer;
      border: 2px solid transparent;
      box-shadow: 0 2px 8px rgba(0,0,0,0.06);
      transition: box-shadow 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
    }

    /* Mnemonic Acronym */
    .mnemonic {
      font-size: 20px;
      font-weight: 900;
      letter-spacing: 1px;
      margin-bottom: 8px;
    }

    /* Fraction equation */
    .equation {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
      font-size: 13px;
      font-weight: 700;
      width: 100%;
    }

    .func-name {
      font-weight: 800;
      white-space: nowrap;
    }

    .fraction {
      display: inline-flex;
      flex-direction: column;
      align-items: center;
      vertical-align: middle;
      line-height: 1.1;
    }

    .numerator {
      border-bottom: 2px solid #1e2945;
      padding-bottom: 2px;
      width: 100%;
      text-align: center;
      font-size: 12px;
      font-weight: 700;
    }

    .denominator {
      padding-top: 2px;
      width: 100%;
      text-align: center;
      font-size: 12px;
      font-weight: 700;
    }

    /* Color Themes */
    /* Blue: SOH */
    .card-soh { border-color: #dbeafe; }
    .card-soh .mnemonic { color: #2563eb; }
    .card-soh .func-name { color: #2563eb; }
    .card-soh.active {
      background: #eff6ff;
      border-color: #2563eb;
      box-shadow: 0 4px 14px rgba(37, 99, 235, 0.18);
    }

    /* Green: CAH */
    .card-cah { border-color: #d1fae5; }
    .card-cah .mnemonic { color: #059669; }
    .card-cah .func-name { color: #059669; }
    .card-cah.active {
      background: #ecfdf5;
      border-color: #059669;
      box-shadow: 0 4px 14px rgba(5, 150, 105, 0.18);
    }

    /* Coral: TOA */
    .card-toa { border-color: #ffe4e6; }
    .card-toa .mnemonic { color: #e11d48; }
    .card-toa .func-name { color: #e11d48; }
    .card-toa.active {
      background: #fff1f2;
      border-color: #e11d48;
      box-shadow: 0 4px 14px rgba(225, 29, 72, 0.18);
    }

    @media (max-width: 380px) {
      .mnemonic { font-size: 17px; }
      .equation { font-size: 11px; }
      .numerator, .denominator { font-size: 10px; }
      .ratio-card { padding: 8px 4px; }
    }
  </style>
</head>
<body>

  
  <div class="triangle-container">
    <svg viewBox="0 0 340 140">
      
      <path d="M 230,115 L 230,100 L 245,100" fill="none" stroke="#94a3b8" stroke-width="2"/>
      
      
      <path d="M 75,115 A 35 35 0 0 0 65,95" class="angle-arc"/>
      <text x="80" y="105" class="angle-label">θ</text>

      
      
      <line id="side-adj" class="side-line" x1="45" y1="115" x2="245" y2="115" stroke="#94a3b8"/>
      
      <line id="side-opp" class="side-line" x1="245" y1="115" x2="245" y2="25" stroke="#94a3b8"/>
      
      <line id="side-hyp" class="side-line" x1="45" y1="115" x2="245" y2="25" stroke="#94a3b8"/>

      
      <text id="lbl-adj" class="side-label" x="145" y="130" fill="#64748b">Adjacent</text>
      <text id="lbl-opp" class="side-label" x="290" y="70" fill="#64748b">Opposite</text>
      <text id="lbl-hyp" class="side-label" x="130" y="55" fill="#64748b" transform="rotate(-24 130 55)">Hypotenuse</text>
    </svg>
  </div>

  
  <div class="cards-grid">
    
    <div id="card-soh" class="ratio-card card-soh active" onclick="selectRatio('soh')">
      <div class="mnemonic">SOH</div>
      <div class="equation">
        <span class="func-name">sin θ =</span>
        <div class="fraction">
          <span class="numerator">Opp</span>
          <span class="denominator">Hyp</span>
        </div>
      </div>
    </div>

    
    <div id="card-cah" class="ratio-card card-cah" onclick="selectRatio('cah')">
      <div class="mnemonic">CAH</div>
      <div class="equation">
        <span class="func-name">cos θ =</span>
        <div class="fraction">
          <span class="numerator">Adj</span>
          <span class="denominator">Hyp</span>
        </div>
      </div>
    </div>

    
    <div id="card-toa" class="ratio-card card-toa" onclick="selectRatio('toa')">
      <div class="mnemonic">TOA</div>
      <div class="equation">
        <span class="func-name">tan θ =</span>
        <div class="fraction">
          <span class="numerator">Opp</span>
          <span class="denominator">Adj</span>
        </div>
      </div>
    </div>
  </div>

  <script>
    const sideOpp = document.getElementById('side-opp');
    const sideAdj = document.getElementById('side-adj');
    const sideHyp = document.getElementById('side-hyp');
    const lblOpp = document.getElementById('lbl-opp');
    const lblAdj = document.getElementById('lbl-adj');
    const lblHyp = document.getElementById('lbl-hyp');

    const cardSoh = document.getElementById('card-soh');
    const cardCah = document.getElementById('card-cah');
    const cardToa = document.getElementById('card-toa');

    const COLOR_SOH = '#2563eb';
    const COLOR_CAH = '#059669';
    const COLOR_TOA = '#e11d48';
    const COLOR_MUTED = '#94a3b8';
    const COLOR_MUTED_TEXT = '#64748b';

    function resetVisuals() {
      [cardSoh, cardCah, cardToa].forEach(c => c.classList.remove('active'));
      [sideOpp, sideAdj, sideHyp].forEach(s => {
        s.setAttribute('stroke', COLOR_MUTED);
        s.style.strokeWidth = '4';
      });
      [lblOpp, lblAdj, lblHyp].forEach(l => l.setAttribute('fill', COLOR_MUTED_TEXT));
    }

    function selectRatio(type) {
      resetVisuals();

      if (type === 'soh') {
        cardSoh.classList.add('active');
        sideOpp.setAttribute('stroke', COLOR_SOH);
        sideOpp.style.strokeWidth = '6';
        lblOpp.setAttribute('fill', COLOR_SOH);

        sideHyp.setAttribute('stroke', COLOR_SOH);
        sideHyp.style.strokeWidth = '6';
        lblHyp.setAttribute('fill', COLOR_SOH);
      } else if (type === 'cah') {
        cardCah.classList.add('active');
        sideAdj.setAttribute('stroke', COLOR_CAH);
        sideAdj.style.strokeWidth = '6';
        lblAdj.setAttribute('fill', COLOR_CAH);

        sideHyp.setAttribute('stroke', COLOR_CAH);
        sideHyp.style.strokeWidth = '6';
        lblHyp.setAttribute('fill', COLOR_CAH);
      } else if (type === 'toa') {
        cardToa.classList.add('active');
        sideOpp.setAttribute('stroke', COLOR_TOA);
        sideOpp.style.strokeWidth = '6';
        lblOpp.setAttribute('fill', COLOR_TOA);

        sideAdj.setAttribute('stroke', COLOR_TOA);
        sideAdj.style.strokeWidth = '6';
        lblAdj.setAttribute('fill', COLOR_TOA);
      }
    }

    // Initialize with SOH active
    selectRatio('soh');
  </script>
</body>
</html>

Trigonometric Ratios in a Right Triangle

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #ffffff;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px;
      user-select: none;
    }

    /* Tabs / Controls */
    .controls {
      display: flex;
      gap: 8px;
      width: 100%;
      max-width: 420px;
      justify-content: center;
    }
    .tab-btn {
      flex: 1;
      padding: 8px 10px;
      font-size: 14px;
      font-weight: 700;
      border-radius: 8px;
      border: 1px solid #e2e8f0;
      background: #f8fafc;
      color: #64748b;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 4px;
      transition: background 0.2s, color 0.2s, box-shadow 0.2s, border-color 0.2s;
    }
    .tab-btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.25);
    }

    /* Main visual grid */
    .stage {
      width: 100%;
      max-width: 440px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
    }

    /* SVG Triangle Container */
    .svg-wrap {
      width: 100%;
      max-width: 380px;
      position: relative;
    }
    svg {
      width: 100%;
      height: auto;
      display: block;
      overflow: visible;
    }

    /* Triangle side paths & labels */
    .side-line {
      stroke-width: 4;
      stroke-linecap: round;
      transition: stroke 0.3s, stroke-width 0.3s, opacity 0.3s;
    }
    .side-label-bg {
      rx: 6;
      ry: 6;
      transition: fill 0.3s, opacity 0.3s;
    }
    .side-label-text {
      font-size: 13px;
      font-weight: 800;
      fill: #ffffff;
      text-anchor: middle;
      dominant-baseline: central;
      font-family: inherit;
    }
    .side-name-text {
      font-size: 11px;
      font-weight: 700;
      text-anchor: middle;
      dominant-baseline: central;
      font-family: inherit;
      transition: fill 0.3s, opacity 0.3s;
    }

    /* Ratio Equation Card */
    .ratio-card {
      width: 100%;
      max-width: 380px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 10px 16px;
      display: flex;
      align-items: center;
      justify-content: space-around;
      min-height: 64px;
    }
    .formula-group {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 17px;
      font-weight: 800;
      color: #0f172a;
    }
    .fraction {
      display: inline-flex;
      flex-direction: column;
      align-items: center;
      vertical-align: middle;
      font-size: 14px;
    }
    .fraction .num {
      padding-bottom: 2px;
      border-bottom: 2px solid #334155;
      width: 100%;
      text-align: center;
      display: flex;
      justify-content: center;
    }
    .fraction .den {
      padding-top: 2px;
      width: 100%;
      text-align: center;
      display: flex;
      justify-content: center;
    }
    .badge {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 2px 8px;
      border-radius: 6px;
      color: #ffffff;
      font-weight: 800;
      font-size: 13px;
      line-height: 1.2;
      box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    }
    .badge-num {
      min-width: 24px;
      padding: 2px 6px;
      font-size: 14px;
    }

    /* Colors */
    .bg-adj { background-color: #059669; } /* Emerald */
    .bg-opp { background-color: #8b5cf6; } /* Purple */
    .bg-hyp { background-color: #f59e0b; } /* Amber */
    
    .text-adj { fill: #059669; color: #059669; }
    .text-opp { fill: #8b5cf6; color: #8b5cf6; }
    .text-hyp { fill: #d97706; color: #d97706; }

    /* Dimmed inactive sides */
    .dimmed {
      opacity: 0.25 !important;
    }
    .highlighted {
      stroke-width: 6 !important;
      opacity: 1 !important;
    }
  </style>
</head>
<body>

  
  <div class="controls">
    <button class="tab-btn active" id="btn-sin" onclick="setRatio('sin')">sin θ</button>
    <button class="tab-btn" id="btn-cos" onclick="setRatio('cos')">cos θ</button>
    <button class="tab-btn" id="btn-tan" onclick="setRatio('tan')">tan θ</button>
  </div>

  
  <div class="stage">
    <div class="svg-wrap">
      <svg viewBox="0 0 320 170">
        
        <polygon points="45,145 275,145 275,35" fill="#f1f5f9" opacity="0.7"/>

        
        <path d="M 260,145 L 260,130 L 275,130" fill="none" stroke="#94a3b8" stroke-width="2"/>

        
        <path d="M 75,145 A 30 30 0 0 0 71.4,132" fill="none" stroke="#0284c7" stroke-width="2.5"/>
        <text x="86" y="136" font-size="14" font-weight="800" fill="#0284c7" dominant-baseline="central">θ</text>

        
        <line id="line-adj" class="side-line" x1="45" y1="145" x2="275" y2="145" stroke="#059669"/>
        <rect id="badge-adj" class="side-label-bg" x="144" y="152" width="32" height="18" fill="#059669"/>
        <text id="val-adj" class="side-label-text" x="160" y="161">12</text>
        <text id="name-adj" class="side-name-text text-adj" x="160" y="133">Adjacent</text>

        
        <line id="line-opp" class="side-line" x1="275" y1="145" x2="275" y2="35" stroke="#8b5cf6"/>
        <rect id="badge-opp" class="side-label-bg" x="282" y="81" width="28" height="18" fill="#8b5cf6"/>
        <text id="val-opp" class="side-label-text" x="296" y="90">5</text>
        <text id="name-opp" class="side-name-text text-opp" x="246" y="90">Opposite</text>

        
        <line id="line-hyp" class="side-line" x1="45" y1="145" x2="275" y2="35" stroke="#f59e0b"/>
        <rect id="badge-hyp" class="side-label-bg" x="144" y="77" width="32" height="18" fill="#f59e0b"/>
        <text id="val-hyp" class="side-label-text" x="160" y="86">13</text>
        <text id="name-hyp" class="side-name-text text-hyp" x="150" y="65">Hypotenuse</text>
      </svg>
    </div>

    
    <div class="ratio-card" id="ratioCard">
      
    </div>
  </div>

  <script>
    const data = {
      sin: {
        name: 'sin θ',
        numText: 'Opposite',
        denText: 'Hypotenuse',
        numVal: '5',
        denVal: '13',
        numBg: 'bg-opp',
        denBg: 'bg-hyp',
        activeSides: ['opp', 'hyp'],
        inactiveSides: ['adj']
      },
      cos: {
        name: 'cos θ',
        numText: 'Adjacent',
        denText: 'Hypotenuse',
        numVal: '12',
        denVal: '13',
        numBg: 'bg-adj',
        denBg: 'bg-hyp',
        activeSides: ['adj', 'hyp'],
        inactiveSides: ['opp']
      },
      tan: {
        name: 'tan θ',
        numText: 'Opposite',
        denText: 'Adjacent',
        numVal: '5',
        denVal: '12',
        numBg: 'bg-opp',
        denBg: 'bg-adj',
        activeSides: ['opp', 'adj'],
        inactiveSides: ['hyp']
      }
    };

    let currentRatio = 'sin';
    const sideKeys = ['opp', 'adj', 'hyp'];

    function setRatio(ratioKey) {
      currentRatio = ratioKey;

      // Update button states
      document.querySelectorAll('.tab-btn').forEach(btn => btn.classList.remove('active'));
      document.getElementById('btn-' + ratioKey).classList.add('active');

      const config = data[ratioKey];

      // Update SVG highlights and dimming
      sideKeys.forEach(side => {
        const line = document.getElementById('line-' + side);
        const badge = document.getElementById('badge-' + side);
        const val = document.getElementById('val-' + side);
        const name = document.getElementById('name-' + side);

        const isActive = config.activeSides.includes(side);
        
        if (isActive) {
          line.classList.remove('dimmed');
          line.classList.add('highlighted');
          badge.classList.remove('dimmed');
          val.classList.remove('dimmed');
          name.classList.remove('dimmed');
        } else {
          line.classList.remove('highlighted');
          line.classList.add('dimmed');
          badge.classList.add('dimmed');
          val.classList.add('dimmed');
          name.classList.add('dimmed');
        }
      });

      // Update equation display
      const card = document.getElementById('ratioCard');
      card.innerHTML = `
        <div class="formula-group">
          <span>${config.name}</span>
          <span>=</span>
          <div class="fraction">
            <div class="num"><span class="badge ${config.numBg}">${config.numText}</span></div>
            <div class="den"><span class="badge ${config.denBg}">${config.denText}</span></div>
          </div>
          <span>=</span>
          <div class="fraction">
            <div class="num"><span class="badge badge-num ${config.numBg}">${config.numVal}</span></div>
            <div class="den"><span class="badge badge-num ${config.denBg}">${config.denVal}</span></div>
          </div>
        </div>
      `;
    }

    // Initial render
    setRatio('sin');
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      color: #1e2945;
      background: #ffffff;
      padding: 12px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
    }

    .panels-container {
      display: flex;
      flex-direction: row;
      justify-content: center;
      align-items: center;
      gap: 8px;
      width: 100%;
      max-width: 600px;
    }

    .triangle-panel {
      flex: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      background: #f8fafc;
      border-radius: 12px;
      padding: 8px 4px 6px;
      border: 1px solid #e2e8f0;
      min-width: 0;
    }

    .panel-header {
      font-size: 13px;
      font-weight: 700;
      padding: 3px 10px;
      border-radius: 20px;
      margin-bottom: 2px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }

    .header-a {
      background: #fef3c7;
      color: #b45309;
    }

    .header-b {
      background: #fef3c7;
      color: #b45309;
    }

    svg {
      width: 100%;
      height: auto;
      max-width: 220px;
      display: block;
      overflow: visible;
    }

    .callout-box {
      width: 100%;
      max-width: 540px;
      margin-top: 10px;
      background: #f1f5f9;
      border: 1.5px solid #cbd5e1;
      border-radius: 10px;
      padding: 8px 14px;
      text-align: center;
      font-size: 13px;
      font-weight: 800;
      color: #0f172a;
      line-height: 1.3;
    }

    .c-hyp { color: #4f46e5; }
    .c-opp { color: #0284c7; }
    .c-adj { color: #059669; }
  </style>
</head>
<body>

  <div class="panels-container">
    
    <div class="triangle-panel">
      <div class="panel-header header-a">Angle A Focus</div>
      <svg viewBox="0 0 200 170" aria-label="Right triangle from angle A perspective">
        
        <polygon points="35,135 165,135 165,30" fill="#ffffff" stroke="#94a3b8" stroke-width="2" stroke-linejoin="round" />
        
        
        <path d="M 147 135 L 147 117 L 165 117" fill="none" stroke="#64748b" stroke-width="1.5" />
        
        
        <path d="M 35 135 L 68 135 A 33 33 0 0 0 60 115 Z" fill="#fde68a" stroke="#d97706" stroke-width="1.5" />
        <circle cx="49" cy="127" r="2.5" fill="#b45309" />
        
        
        
        <line x1="35" y1="135" x2="165" y2="30" stroke="#6366f1" stroke-width="3.5" stroke-linecap="round" />
        
        <line x1="165" y1="135" x2="165" y2="30" stroke="#0284c7" stroke-width="3.5" stroke-linecap="round" />
        
        <line x1="35" y1="135" x2="165" y2="135" stroke="#10b981" stroke-width="3.5" stroke-linecap="round" />

        
        <text x="20" y="142" font-size="13" font-weight="800" fill="#b45309" text-anchor="middle">A</text>
        <text x="165" y="18" font-size="13" font-weight="700" fill="#475569" text-anchor="middle">B</text>
        <text x="178" y="146" font-size="13" font-weight="700" fill="#475569" text-anchor="middle">C</text>

        
        
        <g transform="translate(82, 70) rotate(-39)">
          <rect x="-38" y="-10" width="76" height="18" rx="5" fill="#e0e7ff" stroke="#6366f1" stroke-width="1" />
          <text x="0" y="3" font-size="9.5" font-weight="800" fill="#4338ca" text-anchor="middle">Hypotenuse</text>
        </g>

        
        <g transform="translate(165, 82)">
          <rect x="5" y="-9" width="28" height="18" rx="4" fill="#e0f2fe" stroke="#0284c7" stroke-width="1" />
          <text x="19" y="4" font-size="9.5" font-weight="800" fill="#0369a1" text-anchor="middle">Opp</text>
        </g>

        
        <g transform="translate(100, 135)">
          <rect x="-17" y="5" width="34" height="18" rx="4" fill="#d1fae5" stroke="#10b981" stroke-width="1" />
          <text x="0" y="18" font-size="9.5" font-weight="800" fill="#047857" text-anchor="middle">Adj</text>
        </g>
      </svg>
    </div>

    
    <div class="triangle-panel">
      <div class="panel-header header-b">Angle B Focus</div>
      <svg viewBox="0 0 200 170" aria-label="Right triangle from angle B perspective">
        
        <polygon points="35,135 165,135 165,30" fill="#ffffff" stroke="#94a3b8" stroke-width="2" stroke-linejoin="round" />
        
        
        <path d="M 147 135 L 147 117 L 165 117" fill="none" stroke="#64748b" stroke-width="1.5" />
        
        
        <path d="M 165 30 L 165 63 A 33 33 0 0 1 144 55 Z" fill="#fde68a" stroke="#d97706" stroke-width="1.5" />
        <circle cx="157" cy="46" r="2.5" fill="#b45309" />
        
        
        
        <line x1="35" y1="135" x2="165" y2="30" stroke="#6366f1" stroke-width="3.5" stroke-linecap="round" />
        
        <line x1="165" y1="135" x2="165" y2="30" stroke="#10b981" stroke-width="3.5" stroke-linecap="round" />
        
        <line x1="35" y1="135" x2="165" y2="135" stroke="#0284c7" stroke-width="3.5" stroke-linecap="round" />

        
        <text x="20" y="142" font-size="13" font-weight="700" fill="#475569" text-anchor="middle">A</text>
        <text x="165" y="18" font-size="13" font-weight="800" fill="#b45309" text-anchor="middle">B</text>
        <text x="178" y="146" font-size="13" font-weight="700" fill="#475569" text-anchor="middle">C</text>

        
        
        <g transform="translate(82, 70) rotate(-39)">
          <rect x="-38" y="-10" width="76" height="18" rx="5" fill="#e0e7ff" stroke="#6366f1" stroke-width="1" />
          <text x="0" y="3" font-size="9.5" font-weight="800" fill="#4338ca" text-anchor="middle">Hypotenuse</text>
        </g>

        
        <g transform="translate(165, 82)">
          <rect x="5" y="-9" width="28" height="18" rx="4" fill="#d1fae5" stroke="#10b981" stroke-width="1" />
          <text x="19" y="4" font-size="9.5" font-weight="800" fill="#047857" text-anchor="middle">Adj</text>
        </g>

        
        <g transform="translate(100, 135)">
          <rect x="-17" y="5" width="34" height="18" rx="4" fill="#e0f2fe" stroke="#0284c7" stroke-width="1" />
          <text x="0" y="18" font-size="9.5" font-weight="800" fill="#0369a1" text-anchor="middle">Opp</text>
        </g>
      </svg>
    </div>
  </div>

  <div class="callout-box">
    <span class="c-hyp">Hypotenuse</span> never moves, but <span class="c-opp">Opposite</span> and <span class="c-adj">Adjacent</span> swap!
  </div>

</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      -webkit-tap-highlight-color: transparent;
      user-select: none;
    }

    body {
      width: 100%;
      min-height: 100%;
      background: transparent;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 12px;
      color: #1e2945;
    }

    .nav-tabs {
      display: flex;
      gap: 6px;
      margin-bottom: 12px;
      background: #f1f5f9;
      padding: 4px;
      border-radius: 20px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .tab-btn {
      border: none;
      background: transparent;
      padding: 6px 14px;
      font-size: 13px;
      font-weight: 600;
      color: #64748b;
      border-radius: 16px;
      cursor: pointer;
      transition: all 0.2s ease;
    }

    .tab-btn.active {
      background: #ffffff;
      color: #1e2945;
      box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
    }

    .tab-btn.active[data-target="hypotenuse"] { color: #ea580c; }
    .tab-btn.active[data-target="opposite"] { color: #7c3aed; }
    .tab-btn.active[data-target="adjacent"] { color: #0d9488; }

    .diagram-wrap {
      width: 100%;
      max-width: 440px;
      position: relative;
    }

    svg {
      width: 100%;
      height: auto;
      display: block;
      overflow: visible;
    }

    .side-group {
      cursor: pointer;
      transition: opacity 0.25s ease;
    }

    .side-line {
      transition: stroke-width 0.25s ease;
    }

    .side-hit {
      stroke: transparent;
      stroke-width: 24;
      cursor: pointer;
      fill: none;
    }

    .badge-card {
      transition: transform 0.2s ease, filter 0.2s ease;
      cursor: pointer;
    }

    .dimmed {
      opacity: 0.18;
    }

    .side-group.active .side-line {
      stroke-width: 5;
    }
  </style>
</head>
<body>

  <div class="nav-tabs">
    <button class="tab-btn active" data-target="all" onclick="selectSide('all')">All</button>
    <button class="tab-btn" data-target="hypotenuse" onclick="selectSide('hypotenuse')">Hypotenuse</button>
    <button class="tab-btn" data-target="opposite" onclick="selectSide('opposite')">Opposite</button>
    <button class="tab-btn" data-target="adjacent" onclick="selectSide('adjacent')">Adjacent</button>
  </div>

  <div class="diagram-wrap">
    <svg viewBox="0 0 430 290">
      <defs>
        <filter id="shadow" x="-10%" y="-10%" width="120%" height="130%">
          <feDropShadow dx="0" dy="2" stdDeviation="3" flood-color="#0f172a" flood-opacity="0.08" />
        </filter>
      </defs>

      
      <polygon points="65,225 325,225 325,55" fill="#f8fafc" />

      
      <path d="M 305 225 L 305 205 L 325 205" fill="none" stroke="#94a3b8" stroke-width="2.5" stroke-linejoin="round" />

      
      <path d="M 65 225 L 110 225 A 45 45 0 0 0 102.7 200.3 Z" fill="#e2e8f0" opacity="0.6" />
      <path d="M 110 225 A 45 45 0 0 0 102.7 200.3" fill="none" stroke="#1e2945" stroke-width="2.5" stroke-linecap="round" />
      <text x="86" y="217" fill="#1e2945" font-size="16" font-weight="700" text-anchor="middle">θ</text>

      
      <g id="grp-adjacent" class="side-group active" onclick="selectSide('adjacent')">
        <line x1="65" y1="225" x2="325" y2="225" stroke="#0d9488" stroke-width="3.5" stroke-linecap="round" class="side-line" />
        <line x1="65" y1="225" x2="325" y2="225" class="side-hit" />
        <g class="badge-card">
          <rect x="135" y="240" width="110" height="32" rx="12" fill="#ffffff" stroke="#0d9488" stroke-width="1.5" filter="url(#shadow)" />
          <text x="190" y="261" text-anchor="middle" fill="#0d9488" font-size="13" font-weight="700">Adjacent</text>
        </g>
      </g>

      
      <g id="grp-opposite" class="side-group active" onclick="selectSide('opposite')">
        <line x1="325" y1="225" x2="325" y2="55" stroke="#7c3aed" stroke-width="3.5" stroke-linecap="round" class="side-line" />
        <line x1="325" y1="225" x2="325" y2="55" class="side-hit" />
        <g class="badge-card">
          <rect x="335" y="124" width="90" height="32" rx="12" fill="#ffffff" stroke="#7c3aed" stroke-width="1.5" filter="url(#shadow)" />
          <text x="380" y="145" text-anchor="middle" fill="#7c3aed" font-size="13" font-weight="700">Opposite</text>
        </g>
      </g>

      
      <g id="grp-hypotenuse" class="side-group active" onclick="selectSide('hypotenuse')">
        <line x1="65" y1="225" x2="325" y2="55" stroke="#ea580c" stroke-width="3.5" stroke-linecap="round" class="side-line" />
        <line x1="65" y1="225" x2="325" y2="55" class="side-hit" />
        <g class="badge-card">
          <rect x="125" y="105" width="118" height="32" rx="12" fill="#ffffff" stroke="#ea580c" stroke-width="1.5" filter="url(#shadow)" />
          <text x="184" y="126" text-anchor="middle" fill="#ea580c" font-size="13" font-weight="700">Hypotenuse</text>
        </g>
      </g>

      
      <circle cx="65" cy="225" r="3.5" fill="#1e2945" />
      <circle cx="325" cy="225" r="3.5" fill="#1e2945" />
      <circle cx="325" cy="55" r="3.5" fill="#1e2945" />
    </svg>
  </div>

  <script>
    function selectSide(target) {
      const sides = ['hypotenuse', 'opposite', 'adjacent'];
      
      // Update Buttons
      document.querySelectorAll('.tab-btn').forEach(btn => {
        btn.classList.toggle('active', btn.dataset.target === target);
      });

      // Update Side Elements
      sides.forEach(side => {
        const grp = document.getElementById('grp-' + side);
        if (target === 'all' || target === side) {
          grp.classList.remove('dimmed');
          grp.classList.add('active');
        } else {
          grp.classList.add('dimmed');
          grp.classList.remove('active');
        }
      });
    }
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <title>Trigonometric Ratios in Similar Triangles</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, sans-serif;
      background: #ffffff;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 12px;
      min-height: 100%;
    }

    .main-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      width: 100%;
      max-width: 580px;
    }

    .triangle-card {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      position: relative;
    }

    .card-header {
      font-size: 13px;
      font-weight: 700;
      color: #64748b;
      margin-bottom: 4px;
    }

    .svg-wrap {
      width: 100%;
      height: 150px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    svg {
      width: 100%;
      height: 100%;
      overflow: visible;
    }

    .calc-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      margin-top: 8px;
      font-size: 15px;
      font-weight: 700;
    }

    .fraction {
      display: inline-flex;
      flex-direction: column;
      vertical-align: middle;
      text-align: center;
      font-size: 14px;
      line-height: 1;
    }

    .numerator {
      border-bottom: 2px solid currentColor;
      padding-bottom: 2px;
    }

    .denominator {
      padding-top: 2px;
    }

    .val-opp { color: #0284c7; }
    .val-hyp { color: #8b5cf6; }
    .val-adj { color: #94a3b8; }
    .val-res { color: #0f172a; }

    .bottom-badge {
      margin-top: 14px;
      background: #ecfdf5;
      border: 1px solid #a7f3d0;
      color: #065f46;
      font-size: 14px;
      font-weight: 700;
      padding: 6px 16px;
      border-radius: 999px;
      display: flex;
      align-items: center;
      gap: 8px;
      box-shadow: 0 1px 3px rgba(0,0,0,0.04);
    }

    .badge-icon {
      font-size: 16px;
      color: #059669;
    }

    @media (max-width: 400px) {
      .calc-row { font-size: 13px; gap: 4px; }
      .fraction { font-size: 13px; }
      .bottom-badge { font-size: 13px; padding: 5px 12px; }
    }
  </style>
</head>
<body>

  <div class="main-grid">
    
    <div class="triangle-card">
      <div class="card-header">1× Scale</div>
      <div class="svg-wrap">
        <svg viewBox="0 0 160 130">
          
          <polygon points="35,105 135,105 135,35" fill="#f0f9ff" stroke="#cbd5e1" stroke-width="2" />
          
          
          <path d="M 123 105 L 123 93 L 135 93" fill="none" stroke="#94a3b8" stroke-width="1.5" />
          
          
          <path d="M 55 105 A 20 20 0 0 0 51 93" fill="none" stroke="#0f172a" stroke-width="1.8" />
          <text x="60" y="100" font-size="12" font-weight="bold" fill="#0f172a">θ</text>

          
          <line x1="35" y1="105" x2="135" y2="105" stroke="#94a3b8" stroke-width="2.5" />
          <text x="85" y="122" font-size="13" font-weight="700" fill="#94a3b8" text-anchor="middle">4</text>

          
          <line x1="135" y1="105" x2="135" y2="35" stroke="#0284c7" stroke-width="3.5" stroke-linecap="round" />
          <text x="148" y="74" font-size="14" font-weight="800" fill="#0284c7" text-anchor="start">3</text>

          
          <line x1="35" y1="105" x2="135" y2="35" stroke="#8b5cf6" stroke-width="3.5" stroke-linecap="round" />
          <text x="75" y="62" font-size="14" font-weight="800" fill="#8b5cf6" text-anchor="middle">5</text>
        </svg>
      </div>
      
      <div class="calc-row">
        <div class="fraction">
          <span class="numerator val-opp">3</span>
          <span class="denominator val-hyp">5</span>
        </div>
        <span class="val-res">= 0.6</span>
      </div>
    </div>

    
    <div class="triangle-card">
      <div class="card-header">2× Scale</div>
      <div class="svg-wrap">
        <svg viewBox="0 0 160 130">
          
          <polygon points="20,110 140,110 140,20" fill="#f0f9ff" stroke="#cbd5e1" stroke-width="2" />
          
          
          <path d="M 128 110 L 128 98 L 140 98" fill="none" stroke="#94a3b8" stroke-width="1.5" />
          
          
          <path d="M 40 110 A 20 20 0 0 0 36 98" fill="none" stroke="#0f172a" stroke-width="1.8" />
          <text x="45" y="105" font-size="12" font-weight="bold" fill="#0f172a">θ</text>

          
          <line x1="20" y1="110" x2="140" y2="110" stroke="#94a3b8" stroke-width="2.5" />
          <text x="80" y="125" font-size="13" font-weight="700" fill="#94a3b8" text-anchor="middle">8</text>

          
          <line x1="140" y1="110" x2="140" y2="20" stroke="#0284c7" stroke-width="3.5" stroke-linecap="round" />
          <text x="151" y="69" font-size="14" font-weight="800" fill="#0284c7" text-anchor="start">6</text>

          
          <line x1="20" y1="110" x2="140" y2="20" stroke="#8b5cf6" stroke-width="3.5" stroke-linecap="round" />
          <text x="70" y="58" font-size="14" font-weight="800" fill="#8b5cf6" text-anchor="middle">10</text>
        </svg>
      </div>

      <div class="calc-row">
        <div class="fraction">
          <span class="numerator val-opp">6</span>
          <span class="denominator val-hyp">10</span>
        </div>
        <span style="color:#64748b">=</span>
        <div class="fraction">
          <span class="numerator val-opp">3</span>
          <span class="denominator val-hyp">5</span>
        </div>
        <span class="val-res">= 0.6</span>
      </div>
    </div>
  </div>

  <div class="bottom-badge">
    <span class="badge-icon">✦</span>
    <span>Ratio stays constant!</span>
  </div>

</body>
</html>

Finding Trigonometric Ratios from Side Lengths

Trigonometric Ratios of Complementary Angles

Exact Trigonometric Ratios for 45-45-90 Triangles

Exact Trigonometric Ratios for 30-60-90 Triangles

Fluency Practice: Trigonometric Ratios of 30°, 45° and 60°

Finding Sides of Right Triangles Using Trigonometric Ratios

Finding Angles of Right Triangles Using Trigonometric Ratios

Solving Right Triangles

Right Triangle Trigonometry Word Problems: Angles of Elevation

Right Triangle Trigonometry Word Problems: Angles of Depression

Multi-Step Applications of Trigonometry in Navigation and Surveying

math

Right Triangle Trigonometry and Applications

锐角确定时直角三角形边之比为定值的探究（从相似到三角函数）

正切的概念：对边比邻边 (tan A) 与坡度坡比

正弦的概念：对边比斜边 (sin A)

余弦的概念：邻边比斜边 (cos A)

锐角三角函数的整体概念与自变量取值范围 (0° < A < 90°)

30° 角的三角函数值：利用含 30° 角直角三角形几何推导

45° 角的三角函数值：利用等腰直角三角形几何推导

60° 角的三角函数值：几何推导与特殊角表格记忆

同角与互余两角三角函数关系：sin²A+cos²A=1 与 sin A=cos(90°-A)

锐角三角函数随角度变化的增减性探究

锐角三角函数的概念与特殊角三角函数值

科学计算器三角函数按键认识与角度制 (DEG) 模式设置

由已知锐角用计算器求正弦、余弦、正切值

由已知三角函数值用计算器求对应锐角（反三角函数功能）

度分秒与十进制角度的互化及计算器转换键 (DMS / ° ' ") 操作

含 30°、45°、60° 特殊角三角函数式的精确混合运算

不查表与不按计算器比较锐角三角函数值的大小

三角函数计算中的四舍五入精确度要求与误差控制

“知一求五”：已知一个锐角三角函数值构造直角三角形求其它函数值

结合方程与代数变换求解三角函数未知角

用计算器探索三角函数规律与运算错例反思

计算器应用与锐角三角函数的运算

解直角三角形的概念与边角五元素关系

基本类型一：已知两边（两直角边或一直角边一斜边）解直角三角形

基本类型二：已知一边一锐角解直角三角形

仰角与俯角问题：测量建筑物与无人机高度

方向角（方位角）问题：航海避礁与航空飞行定位

坡度与坡角问题：堤坝防洪与公路铁路工程坡比计算

化一般三角形为直角三角形：作高线（分割或补形）解题策略

OGM.9.TRN.3

Aligned learning resources

Related diagrams