find the total surface.area of a regular pyramid with a square base if each edge of the bars measures 16. inches the slant height of a side is 17 inches and the altitude is 15 inches the perimeter of the bars is 4s since it is a square p=4(16)=64 inches the area of the base is s2 B=16 2 =256 inches 2 t.s.a.=1/2(64)(17)+256 =544+256 =800 inches2