Recall the formula for volume of a cube; Length * Height * Width = Volume. Well in a cube, all sides are the same value. So L = H = W. So any variable can be used as all three measurements. So x * x * x = 27 cubic cm. We can simplify this into x^3 =27. Cube-root each side to end up with x = 3 cm. Length, Height and Width are all 3 cm.
