I made another post about Finding angles of Polygons as a few of my students had difficulty solving such questions such as the one above during the E-Math Prelim Exams. For i) above, the faster way to solve is to use exterior angle = 360 degrees /n ( the sum of exterior angles of any polygon is 360 degrees), then take 180 degrees -exterior angle=interior angle. As for the solution above,I chose to use a longer method because it is more intuitive for most students. In part iii) and v) above, you need to remember that in a regular polygon, besides all interior angles being equal and all exterior angles equal, the length of every side is also equal. When sides are equal, you can form isosceles triangles to help you to solve the question.