JAMB - Mathematics (2015 - No. 56)
How many sides has a regular polygon whose interior angles are 120°each
4
5
6
3
Explication
Each exterior angle = 180 − 120=60
Exterior angle =360/n
60 = 360/n
n =360/6
= 6
Exterior angle =360/n
60 = 360/n
n =360/6
= 6