Fact #1:
A cube has six faces.
Fact #2:
Every one of them has the same area.
Fact #3:
The surface area of each face is (the length of the cube's side)²
Now that I look at this one more carefully, the only thing you need to know
to solve it is Fact #3. (But you can keep the others and save them for later.)
The surface area of each face is (the length of the cube's side)²
64 is the (length of the cube's side)²
Can you find a number that gives you 64 when you multiply it by itself ?
That's the length of the cube's side.
Hint: If you don't get ' 8 ', work on it a little more.