If the sum of all the interior angles of an octagon is 1080°, which of the following is the correct equation to use in finding the sum of interior angles? (NOTE: S stands for the SUM and N the NUMBER OF SIDES of a given polygon) a. S= (n-1)(180)
b. S= (n+1)(180)
c. S= (n) 180
d. S= (n-2)(180)
b. S= (n+1)(180)
c. S= (n) 180
d. S= (n-2)(180)