
Sum of the interior angles of a polygon is (n  2) 180 or (2n  4) 90 where n is the number of sides of a polygon
Note: The sum of the interior angles of a convex polygon is (2n4) 90 or (n2)180. Directions: Using the above formula, draw and find the sum of the interior angles for the following figures: triangle, rectangle, square, rectangle, parallelogram, pentagon, hexagon, heptagon, octagon, nonagon and decagon. 