Expert: Steve Holleran - 3/16/2007

Question
Find the length of the side of a cubic box whose volume is 80 cubic feet.

I'm pretty sure the formula is V=lWH but without other given variables I'm stumped.

Please help

Answer
Hi Monte,

You are right about the formula, and the problem is not as hard as you may think.  The saving grace here is that we are dealing with a cube.  In a cube, all edges are the same length, so while the volume formula is

                    V = L * W * H

In a cube, you can call L = W = H = x, since they are equal.

That gives you

                   V = x * x * x = x^3

So now, if V = 80 cu ft,

                   80 = x^3  and x = cube rt (80) = 4.31


So each side of the cubic box is approx. 4.31 ft.

I hope this helps you out.

Steve Holleran