The dimension of front face is l=4 ft and b=12 ft.
Determine the area of each front face of prism.
[tex]\begin{gathered} A_1=4\times12 \\ =48 \end{gathered}[/tex]
The dimension of top face is l=4 ft and b=7 ft.
Determine the area of each top face.
[tex]\begin{gathered} A_2=4\times7 \\ =28 \end{gathered}[/tex]
The dimension of side face is l=7 ft abd b=12 ft.
Determine the area of each side face.
[tex]\begin{gathered} A_3=12\times7 \\ =84 \end{gathered}[/tex]
Determine the total surface area of prism.
[tex]\begin{gathered} A=2A_1+2A_2+2A_3 \\ =2\times48+2\times28+2\times84 \\ =96+56+168 \\ =320 \end{gathered}[/tex]
So total surface area of prism is 320 square feet.
