Question

find the number of sides of a regular polygon if each interior angle is 168 degree

Answer 1

Each Interior Angle =  180 (n-2) / n. where n is no. of sides

Given Each interior angle = 168°

168 = 180n - 360 / n

168n = 180n - 360

180n - 168n = 360

12n = 360

n = 30

No. of sides = 30

Answer 2

Answer:

each interior angle of regular polygon

= (n - 2) × 180°

n

168° = (n - 2) × 180°

n

168n = 180n - 360°

168n - 180n = -360°

-12n = -360°

n = -360°

-12

n = 30

Hence the polygon has 30 sides.