Answer:
156
Step-by-step explanation:
Each triangle has an angle sum of 180 degrees, so the sum of the interior angles of the 15-gon must be (n-2) 13 × 180 = 2340 degrees. Since the 15-gon is regular, this total is shared equally among the 15 interior angles. Each interior angle must have a measure of 2340 ÷ 15 = 156 degrees.
