we know that
The surface area of a cube is equal to
[tex] S=6*A [/tex]
where
A is the area of one face of the cube
in this problem
[tex] A=8.5^{2}= 72.25\ in ^{2}[/tex]
Find the surface area
[tex] S=6*72.25=433.5\ in ^{2} [/tex]
therefore
the answer is
[tex] 433.5\ in ^{2} [/tex] of wrapping paper is needed to cover the box completely
