We're finding how much surface he needs in order to entirely wrap the box, so let's use the surface area form to find it.
[tex]SA: A_1 + A_2 + A_3[/tex]
[tex]A_1 = 2(5 \cdot 3)[/tex] (front and back)
[tex]A_2 = 2(3 \cdot 14)[/tex] (two sides)
[tex]A_3 = 2(5 \cdot 14)[/tex] (top and bottom)
Hence, our SA becomes [tex]2(5 \cdot 3) + 2(3 \cdot 14) + 2(5 \cdot 14)[/tex]
[tex]= 254 ft^{2}[/tex] of wrapping paper.
