Find the volume of the rectangle:
8 x 2 x 4 = 64 cubic inches.
This means the square can have a volume of 64 cubic inches.
The formula for the volume of a square is V = S^# where S is the length of the side.
Replace V with 64 to solve for S:
64 = S^3
To find S, take the cubic root of 64:
S = ∛64
S = 4
The length of a side is 4 inches.