A polygon has an interior angle sum of 2520 degrees. How many sides must the polygon have?

So since the formula for the sum of a polygon's interior angles is (n-2)180, just make that equal to 2520 and solve for n, which is the number of sides.

STEPS:

1) (n-2)180 = 2520

2) n-2 = 2520/180

3) n-2 = 14

4) n = 16

So the polygon must have 16 sides