Answer:
16
Step-by-step explanation:
The sum of the interior angles of a polygon is
sum = 180° (n - 2) ← n is the number of sides
Here the sum is 2520, thus
180° (n - 2) = 2520 ( divide both sides by 180 )
n - 2 = 14 ( add 2 to both sides )
n = 16
The polygon has 16 sides.