Question

If in a regular polygon each exterior angle is twice the interior angle then the number of sides will be
a)4
b)3
c)5
d)6

Answer 1

Let the interior angle be x degrees and interior angle is 2x degrees.
we know that the sum of interior and exterior angles of a polygon sum to 180 degrees.
x + 2x = 180
on solving we get x = 60 degrees.
Since, exterior of a polygon = 360/no. of sides 
60 = 360/no. of sides 
no. of sides = 360/60
Therefore no. of sides will be 6.

Hope this helps you out.