This demonstrates that the angle sum is 180[sup]o[/sup] times the number of triangles, which is 2 less than the number of sides. 180[sup]o[/sup] (n – 2)

This demonstrates that the angle sum is 360[sup]o[/sup] less than 180[sup]o[/sup] times the number of triangles drawn from the center. 180[sup]o[/sup] n – 360[sup]o[/sup]