I found a lite version of the Sum of Exterior Angles which helps students explore that all the exterior angles add up to 360 degrees always. This might be a nice way to help students learn the material but I am also wondering if we could accomplish the same thing using one of the apps I already have on the iPad.
I know I can use the geoboard to help students constructively learn that the total interior angles is based on the number of triangles you can subdivide the figure into. I am wondering if I extended the side further out so that students could see that the exterior angle. On the other hand, the Sum of Exterior Angles lite allows students to explore this concept using both regular and nonregular polygons. Maybe I will just download it and see how it actually works.