Answer: the polygon has 20 sides.
Explanation:
The formula for determining the sum of the measure of the interior angles in a regular polygon is expressed as (n - 2) × 180.
if the sum of the measures of the interior angles is 3960
degrees. This means that
(n - 2) × 180 = 3960
Expanding the brackets by applying the distributive property, it becomes
180n - 360 = 3960
180n = 3960 - 360
180n = 3600
Dividing both sides by 180, it becomes
n = 3600/180
n = 20