geometry
posted by JOY .
A pyramid has a square base with each side measuring 105.5 meters. The slant height of the pyramid is 65.5 meters. Find the lateral surface area of the pyramid.

P = 4 * 105.5 = 422m = perimeter of the base.
Al=P*Hs / 2 = 422 * 65.5 / 2=13,821m^2.