Answers

2015-11-02T20:27:48+05:30
Interior angle a regular polygon of n sides = (n - 2) × 180 / n

(n - 2) × 180 / n = 120
(n - 2) × 180 = 120n 
180n - 360 = 120n 
60n = 360
n = 6
∴ The regular polygon has 6 sides(hexagon).

1 5 1
Hope it helps :) and if it does please click on thanks button above & mark as best answer ^_^