The following applet can be used to approximate the area of a unit circle by using regular polygons. The user may select between either inscribed or circumscribed polygons to approximate the area of the circle. The applet can also be used to graph the sequences of areas.

Simply select the value of n and the applet automatically draws the appropriate regular n-sided polygon and displays the area of the polygon.

Historical Note: Archimedes (287-212 B.C.) came up with this idea over two thousand years ago to approximate the value of π. By hand, Archimedes used regular 96-gons to correctly approximate π to two decimal places.