OER Commons
Oer Commons: Polygons
Seventh graders find the area of regular polygons, recalling what they already know about the area of geometric shapes and generalizing a formula for any regular polygon.
Better Lesson
Better Lesson: Area of Triangles
Sixth graders apply what they know about area of other polygons to develop a formula for finding the area of a triangle.
Illustrative Mathematics
Illustrative Mathematics: 6.ee Rectangle Perimeter 2
This task is a natural follow up for task Rectangle Perimeter 1. After thinking about and using one specific expression for the perimeter of a rectangle, they now extend their thinking to equivalent expressions for the same quantity....