An interior angle of a regular polygon is 5 times its exterior angle. Then the number of sides of the polygon is
14
16
12
18
C.
12
Sum of interior and exterior angle = 180°
I + E = 180°
Let the exterior angle be x.
Number of sides of polygon:
The measure of an angle whose supplement is three times as large as its complement, is
60°
75°
30°
45°