angles of a polygon with n sides is (n – 2)180. The measure of each interior angle of an equiangular n-gon is. If you count one exterior angle at each vertex, the sum of the measures of the exterior angles of a polygon is always 360 degrees. a parallelogram is a quadrilateral with two pairs of parallel sides. The opposite or facing sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure.
