Find the value of y if the measures of the interior angles of a convex decagon are 5yº, 5yº, 8yº, 8yº, 9yº, 9yº, 9yº, 9yº, 9yº, and 9yº.
+37146 Sum of convex decagon interior angles = 1440 ( that is (10-2 * 180) )
(5 *2 + 8*2 + 9*6) y = 1440
80y = 1440 solve for y
