Question

Find the measure of one interior angle of a regular 21-gon.

A. 160
B. 162.9
C. 165.6
D. 165

Answer 1

C step-by-step the coordinate of that is pretty simple to say but hard at the same time

Answer 2

Measure of sum of interior angles formula (where “n” is number of sides): (n-2)180

(21-2)180
=3420

3420 is the measure of the sum of a regular 21-gon, and to find the measure of only one angle, we need to divide the sum by the number of sides, so
3420/21

= 162.9

the answer is B