Answer:
4 feet.
Step-by-step explanation:
The formula of a cube's volume is V = l*w*h
All 3 in a cube's case are equal
So the volume is V = s*s*s.
In other words all of the sides must be equal
The size of s = cube root of (V)
s = cube root (64)
s = 4.
You might want to check to see if that is correct
4 * 4 * 4
16 * 4
64
Looks like the answer is 4