If you simply it down you get

so X can technically be any number
Slope= y/x so first let’s find the difference in the y coordinates. -6 and 3. -6 + 9= 3
So far we have 9/x, now on to the x coordinates. -3 and 0, -3 + 3 = 0
9/3 is the slope
now simplify and the slope is 3
first polygon
ext. angle=180°-120°
=60°

n=360°/60°
n=6
second polygon
n=2(6)=12
ext. ang= 360°/n = 360°/12° = 30°
int. ang = 180°-30°= 150°
answer is C
Answer: C) 150°
Step-by-step explanation: all the angles are the same