Public learning track
Classifying and Comparing 2D Shapes: Triangles and Quadrilaterals
3rd Grade · Math · Open Global Math
8 lessons
Goal
Classify, describe, and compare triangles and quadrilaterals by side lengths, angle types, and parallel or perpendicular side properties.
Featured Diagrams
Classifying Triangles by Angles: Acute, Right, Obtuse
8 lessons
0 of 8 done
- 1Classifying Triangles by Angles: Acute, Right, ObtuseUp nextStart
- 2Classifying Triangles: Equilateral, Isosceles, and ScalenePremiumNot started yet
- 3Combining Triangle Attributes by Sides and AnglesNot started yet
- 4Sorting Squares, Rectangles, and RhombusesNot started yet
- 5Understanding Trapezoids and Non-Parallelogram QuadrilateralsNot started yet
- 6Quadrilateral Hierarchies: True or False StatementsNot started yet
- 7Drawing Polygons with Specified Side and Angle PropertiesNot started yet
- 8Comparing Regular and Irregular PolygonsNot started yet
Standards Covered
- OGM.4.G.1Open Global Math Standards 2026™ · Math · Level 4 / Grade 3 (Age 8) · Grade 3Classify, describe, and compare two-dimensional shapes (triangles: acute, right, obtuse, isosceles, equilateral; quadrilaterals: rectangles, squares, rhombuses, parallelograms, trapezoids) and three-dimensional solids (cubes, rectangular/triangular prisms, pyramids, cylinders, cones, spheres) based on sides, vertices, edges, and face properties.
- OGM.4.G.3Open Global Math Standards 2026™ · Math · Level 4 / Grade 3 (Age 8) · Grade 3Recognize line segments, rays, and straight lines; identify horizontal, vertical, oblique, parallel, and perpendicular lines; understand that the shortest line between two points is a line segment and use straightedge/rulers to draw line segments and polygonal paths.
Curriculum Framework
3rd Grade · Math · Open Global Math
1
8 lessons
Lines, Rays, Line Segments, and Intersections
Identify and draw points, lines, line segments, rays, horizontal, vertical, oblique, parallel, and perpendicular lines, and understand paths between points.
2
9 lessons
Angles as Turns, Classification, and Protractor Measurement
Understand angles as geometric turns, classify acute, right, obtuse, and straight angles, and measure and draw benchmark angles using protractors.
3
8 lessons
Classifying and Comparing 2D Shapes: Triangles and Quadrilaterals
Classify, describe, and compare triangles and quadrilaterals by side lengths, angle types, and parallel or perpendicular side properties.
4
6 lessons
Partitioning Shapes and Equal-Area Fractions
Partition 2D shapes into equal-area parts, represent each part as a unit fraction of the whole, and understand that equal-area parts can have different shapes.
5
7 lessons
Three-Dimensional Solids, Faces, Edges, Vertices, and Nets
Analyze properties of 3D solids (prisms, pyramids, cylinders, cones, spheres), connect solids to 2D nets, and construct 3D geometric models.
6
7 lessons
Symmetry, Reflections, Translations, and Rotations
Identify lines of symmetry, perform and describe reflections, translations, and rotations, and analyze geometric patterns in nature and art.
7
9 lessons
Grid Coordinates, Maps, Compass Directions, and Multi-View Perspectives
Read and create grid maps, navigate using cardinal and intercardinal compass directions and perspective relative positions, and interpret multi-view elevations of 3D objects.