A square pyramid has faces that are equilateral triangles with sides 8 ft long. What is the volume of the pyramid to the nearest tenth of a cubic foot?
the square base has area 64 and then we use the Pythagorean theorem to solve for the height. 4sqrt3^2=h^2+4^2, so 48=h^2+16, and h^=32, or 4sqrt2. 4sqrt2*64/3, which is approximately 120.7 cubic feet.