Use S=(n-2)180 S is the sum and N is the number of sides If you know that the sum is 7560 then plug that in for S 7560=(n-2)180 Then solve for n 7560=180n-360 (note I used distributive property) 7560+360=180n 7920=180n 7920/180=n n=44 sides I hope this helps :)
