# Interior and exterior angles in regular polygons

- Author:
- Charlie Michaelson, Paul Smith

Investigate the interior and exterior angles in a range of regular polygons.

Record the interior and exterior angles in each different regular polygon. What is the relationship between the number of sides and each of the two angles?

Make the polygon have 8 sides. (n=8) If you added up all 8 interior angles, what would the total sum be?

Now try the formula: (n-2) * 180 n=8, so (8-2)*180 What value do you get?

Look back at the figure. What would the sum of all 8 exterior angles be?

Now change n to any other value. Check the interior angle sum again. Does the formula still work? What would the sum of all exterior angles be now?