[tex]\begin{gathered} \text{Surface area =(8ft)(8ft)+4(}\frac{(8ft)(16ft)}{2}) \\ Surfacearea=64ft^2\text{+4(}\frac{128ft^2}{2}) \\ Surfacearea=64ft^2\text{+4(}64ft^2) \\ Surfacearea=64ft^2\text{+256}ft^2 \\ Surfacearea=320ft^2 \\ \text{The surface area is }320ft^2 \end{gathered}[/tex]
