Question 758987
A square with a diagonal = 8ins
8^2 = 64
64/2 = 32
A side of this cube measures root 32
Volume of cube = length^3
(root 32)^3 = 128 square root 2 ins^3

Surface area = length^2 x 6
             = (root 32)^2 x 6
             = 192 inches^2
Hope this helps.
:-)