Grade 6 · Math · Lesson 19

Angles, Triangles and Polygons

Geometry is the study of shapes — the lines, angles, and figures that fit together to build everything from a triangle on a roof to the hexagons on a honeycomb. In this lesson you will sort angles by how wide they open, name triangles by their sides and angles, and recognize polygons by counting how many straight sides they have.

What this lesson teaches

1Classify angles as acute, right, obtuse, straight, or reflex by their degree measure
2Identify triangles by side lengths and by their largest angle
3Name polygons up to a hexagon by counting their sides
4Describe the difference between regular and irregular polygons

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