Answer:
if thisa is a triangle then 180-30+30 = 120 degree and we say all angles on a triangle add up to 180
Then reaply the rule changing 180 to 360 on all 4 sided shapes
180(n-2) to all other shapes.
ie) pentagon 180(n-2) = 540
continue with 540-30-30 = 480 etc....
Step-by-step explanation: