[Free Registration/Login may be required to access all resource tools.] Find interior angle measures of polygons by drawing diagonals to create triangles.

Find a definition of regular polygon, and learn how to calculate the internal angle, external angle, and number of diagonals of a regular polygon. Also, learn how to find the area of regular polygons.

[Free Registration/Login may be required to access all resource tools.] In this lesson students calculate the area and perimeter of a rhombus or kite. Students examine guided notes, review guided practice, watch instructional videos and...

Explore polygons with Wang, a ricksha puller. Answer his questions and he will give you a free ride!

MathWorld provides the definition of a rectangle and the area formula of a rectangle.