Question

Find the measure of each interior angle of a regular octagon.

A 135
B 1,080
C 180
D100

Find the sum of the interior angles of a nonagon.

A 140
B 1,620
C 1,260
D 1,450

Answer 1

ok, here the formula measure of each interior angle of regular n-gon

`{180}^(0) - \frac{ {360}^(0) }{n}`

octagon ~ 8-gon, so

180° - 360°/8 = 135° (A)

for the sum, we just need multiply the formula above with n

nonagon ~ 9-gon

sum = 9(180° - 360°/9)

= 9(140°) = 1260 (C)