math11
posted by Just a question .
The roof of a building is shaped like a square pyramid, with a base of 18m by 18m. If the slant height of the roof is 12m and roofing costs 5.75m2, how much will it cost for roofing material?
if the pyramid has 4 sides does each side have 18m?

You have four triangles of base 18 and altitude 12
area = 4 * (1/2) * 18 * 12
multiply area by 5.75 to get cost 
area roof= 4*1/2 * 18*12
cost= area * $5.72 That is pretty cheap roofing, about 50cents/square foot. 
thanks