ANSWER
73.5 in²
EXPLANATION
To find the surface area, we have to find the area of one face - one of the squares of the diagram - and then multiply that by 6 - because cubes have 6 faces.
The area of one face is:
[tex]A_{\text{face}}=3.5^2in^2=12.25in^2[/tex]
The surface area of the box is:
[tex]\begin{gathered} S_{}=6A_{\text{face}} \\ S=6\cdot12.25in^2^{} \\ S=73.5in^2 \end{gathered}[/tex]
