Question

The equation above can be used to calculate the volume V, of a pyramid with a height h and base with length l and width w. If the volume of a pyramid is 81inches^3, and l=w=3h, what is the length of the base of the pyramid in inches?

Answer 1

Volume of a pyramid is V= lwh/3
You know
V=81
l=3h
w=3h

h=3
l=9
w=9

So length is 9 inches

Answer 2

Comment
The formula for a pyramid = (1/3) L * W * h The base in this case is square.

Givens
L = W
W =W
L = 3H
H = L/3 = (1/3L)
V = 81 in^3

Solve
V = 1/3 L * W * H
V = 1/3 L * L * 1/3 L
81 = 1/9 L^3 Multiply through by 9
81 * 9 = L^3
729 = L^3 Take the cube root of both sides.
cube root (L^3) = cube root (729)
L = 9 in