The ratio of the internal angle to the external angel in a regular polygon is 13:2 . How many sides does the polygon have?
A ) 7
B ) 20
C ) 15 ✅
D ) 20
Explanation:
13x+2x=180 →15x=180 →x=180/15→x=12,The exterior angle is 2x → 2x=2*12=24.The sum of the exterior angles of a polygon is360. 360/24=15 The polygon has 15 sides.