If a 12-sided regular polygon rotates about its center, at which angle of rotation will the image of the polygon coincide with the preimage?
a. 75°
b. 45°
c. 36°
d. 30°

D) 30

A polygon can rotate a total of 360. This one has 12 sides and 12 angles that are all congruent. So to coincide with original image, it must rotate 1/12 of the way around

360/12=30

12+3b -1=-5-b -12-1+5=-b-3b -8=-4b