1. not sure - try

http://mathforum.org/library/problem..._rttris.html2. Finding the sum of the exterior angles of a polygon is simple. No matter what type of polygon we have, the sum of the exterior angles is ALWAYS equal to 360ÂºDivide 360 by 12 (assuming they are equal angles). 3. it does not specify interior or exterior, but i assume they mean interior.to find interior angles of a polygonsum of angles = (n â€“ 2)180Â°n = total number of sides... that's 5(5 - 2) x 180 = 54030+70+120+165 = 385540 - 385 = 155