You can
put this solution on YOUR website!the height , slant height, and half the width of the base form a right triangle
the ratio of the height to the slant height is 4 to 5 __ sound familiar?
a ?-4-5 right triangle?
half the width of the square base is 9, so the area of the base is 18^2 or 324
volume is 1/3(base area)(height) __ (1/3)(324)(12)=1296