What is the size of an exterior angle of a regular pentagon?

A.
36^{o} 
B.
60^{o} 
C.
72^{o} 
D.
120^{o} 
E.
360^{o}
Correct Answer: Option C
Explanation
Pentagon is a polygon with 5 sides. Sum of interior angles of polygon (regular) = (2n – 4) x 90o
= 5
= (10 – 4) x 90o
= 540o
each interior angle = (frac{540}{5})
= 108o
= 180o let x represent ext. angle
x + 108o = 180v
x = 180o – 108o
= 72o