If the side lengths are all 6 units, then the surface area and volume are the same
surface area = 6*s^2 = 6*6^2 = 216
volume = s^3 = 6^3 = 216
You can find this by solving s^3 = 6s^2 for s to get s = 0 or s = 6. The solution s = 0 is trivial so you can ignore it.
