how do I find the volume of a pyramid with a square base, 20 meters on each side, and a height of 21 meters

Answer 1

V = 1/3 * base area * height

V = (1/3)(400)(21)
V = 2,800 cubic meters

Answer 2

http://www.mathsisfun.com/geometry/square-pyramid.html

Answer 3

Volume of a pyramid is
1/3 times area of base times ht
base is 20(20)= 400 height=21

V= 1/3(400)(21)cubic units