The interior angle of a regular polygon is twice the exterior angle. How many sides has the polygon?

A.
5 
B.
6 
C.
8 
D.
9
Correct Answer: Option B
Explanation
Let the exterior angle = d
Note: Exterior angle + Interior angle = 180°
(implies) d + 2d = 180°
3d = 180° (implies) d = 60°
Recall, exterior angle = (frac{360}{text{no of sides}})
(therefore text{No of sides} = frac{360}{60})
= 6 sides