Khan Academy Static

Polygons are many-sided figures, with sides that are line segments. Polygons are named according to the number of sides and angles they have. The most familiar polygons are the triangle, the rectangle, and the square. In this topic we will learn about the exterior angle property, interior angle property, and we will also practice with some exercises related to polygons.

8518_Sum_of_interior_angles_of_a_polygon.html