Answer:
Sry if it is wrong..........
Answer:
1:
we have a rule that is (n-2)×180
while n = number of sides
2:
exterior angle of a polygon = 360 ÷ number of sides
so 360÷25=14.4
3:
octagon is 8 side, so as we said: (8-2)×180 = 1080
4:
lets make an equation, we know that (n-2)×180 = the sum
so (x-2)×180=720
180x -360 = 720
180x = 1080
x=6
