Geometry- Polygon Interior and Exterior Angles?

You could easily answer those kind of questions in regular polygons by always remembering 2 things: First, get the supplement of the interior angle, this is always 180 degrees minus the interior angle. In question #1, it would be 180 -144=36 degrees. Second, the sum of all supplement angle in a regular polygon is 360 degrees. Since it is a regular polygon, 360 / 36 = 10 equal sides. Try that on question two and three. #2 answer is 6 equal sides #3 answer is 20 equal sides. I am not a teacher, I only learned that in school. I hope I had explained the trick clearly, it does not fail. It's different in irregular polygon. Good luck.