Date: Feb 1, 2011 6:35 AM
Author: Michael de Villiers
Subject: Re: Sum of Interior Angles of Polygons: A general Formula, and other updates
Perhaps it's necessary to point out that this general formula for the sum of interior angles of a polygon is derived from the exterior angles result, namely the Turtle Closed Path theorem.

Students understanding and acceptance of the Turtle Closed Path theorem as an axiom can easily be developed from carefully designed LOGO (turtle geometry) activities. The turtle movement can also be simulated, of course, by animation with other dynamic geometry software.