lesson
Equal Tangents from an External Point: Theorem and Proof
Prove and apply the theorem that tangent segments to a circle from an external point are equal in length.
Updated 1 month ago · 3 views
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This lesson is part of a track
Public learning track
Circle Foundations, Pi, Circumference, and Arcs
9 lessons
Goal
Define pi, calculate circumference and arc length, and analyze chords, tangents, and central and inscribed angles.
9 lessons
0 of 9 done
- Defining Circles, Radii, Diameters, and PiUp next
- Calculating Circumference Using Exact and Approximate Values of PiNot started yet
- Central Angles and Arc MeasureNot started yet
- Calculating Arc Length as a Fraction of CircumferenceNot started yet
- Chords and Perpendicular Bisector Properties in CirclesNot started yet
- Tangent Lines and Radius PerpendicularityNot started yet
- Equal Tangents from an External Point: Theorem and ProofYou are here
- Inscribed Angle Theorem and CorollariesNot started yet
- Angles Formed by Tangents, Secants, and ChordsNot started yet
Learning standards covered
OGM.8.GEO.4Open Global Math Standards 2026™ · 7th GradeUnderstand circles, define pi (pi = C/d), derive formulas for circumference and area of circles and sectors/arcs, solve related composite area problems, and explore fundamental circle properties (chords, tangents, central/inscribed angles).
OGM.8.GEO.6Open Global Math Standards 2026™ · 7th GradeUnderstand deductive reasoning, definitions, conditional propositions, converse statements, theorems, and proof techniques including direct synthetic proof, counterexamples, and proof by contradiction.