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

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

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)

  the correct choice is marked

step-by-step explanation:

the first two graphs show multiple turning points. the last graphs matches the description in every detail.