First thing you must do is find the number of sides of the polygon. The sum of all the exterior angles of a polygon is always 360°. 360/15 = 24 The polygon has 24 sides.
The formula for the sum of the interior angles of a polygon is: 180(n - 2) Where n is the number of sides.
180(24 - 2) 180(22) 3960
The sum of the measure of the interior angles of the polygon is 3960.
Two whole numbers will end up like this: 8x8=64,but multiplying a whole and a decimal will end up like this 8x8.1=64.1 or 8x8=8 to the second power. this should be sufficient information.