Question 3244
The exterior angle is the supplementary angle to the interior angle of the polygon. In other words if E is the exterior angle and I is the interior angle, {{{E + I = 180}}}. To find the interior angle of a regular polygon you can use the formula {{{S = 180 - (360/n)}}}, where S is the interior angle and n is the number of sides in the polygon. So for a regular pentagon the interior angle S is {{{S = 180 - (360/5) = 108}}} degrees. The exterior angle is {{{180 - 108 = 72}}} degrees.