If all angles are 108 degrees how many sides is there for a regular polygon

Sum of interior angles = 180(n-2)
Where n= the number of sides in the polygon

A polygon is called a regular polygon when all of its sides are the same length and all of its angles are the same measure.A regular polygon is both equilateral and equiangular. To find the sum of its interior angles, substitute n = 5 into the formula 180(n - 2) and get 180(5 - 2) = 180(3) = 540°

Since the pentagon is a regular pentagon, the measure of each interior angle will be the same.
  To find the size of each angle, divide the sum, 540º, by the number of angles in the pentagon.
(which is the same as the number of sides).
540°  5 = 108°

There are 108° in each interior angle of a regular pentagon. N=8