I'll do problem 23 to get you started.
S = sum of the interior angles of a polygon with n sides
S = 180(n-2)
Plug in S = 1080 which is given to us and solve for n.
180(n-2) = 1080
n-2 = 1080/180
n-2 = 6
n = 6+2
n = 8 is the final answer to problem 23
The polygon in problem 23 is an octagon.