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put this solution on YOUR website!The sum of the interior angles of a polygon are given by the formula:
(n-2) * 180
n is the number of sides of the polygon.
Triangle = 3 - 2 = 1 * 180 = 180
Quadrangle = 4 - 2 = 2 * 180 = 360 (rectangle, square, Parallelogram, etc).
Pentagon = 5 - 2 = 3 * 180 = 540
hexagon = 6 - 2 = 4 * 180 = 720
etc.