The volume of any rectangular prism equals length X width X height, or

V = lwh

A cube is a special rectangular prism in which all sides (s) are equal in length, such that length = width = hieght or

l = w = h

Because they are all equal, with squares and cubes, we usually use the term side for all three of them. Therefore,

Volume = side X side X side or

V = s^3

So, in your problem, if V = 27, since V = s^3

s^3 = 27

Taking the cube root of each side, we get the result of:

s = 3

Hope this helped.