Answer:
2271.12 in²
Step-by-step explanation:
Surface area of rectangular prism:
[tex]\sf l = length = 42 \dfrac{1}{2}=\dfrac{85}{2} \ in \\\\\\w =width = 18 \ in\\\\h = depth = 6\dfrac{1}{8}=\dfrac{49}{8} \ in[/tex]
[tex]\boxed{\text{\bf Surface area of rectangular prism = 2*(lw + wh + hl)}}[/tex]
[tex]\sf = 2*\left (\dfrac{85}{2}*18 + 18*\dfrac{49}{8 }+ \dfrac{49}{8}*\dfrac{85}{2}}\right)\\\\\\=2*\left(85*9 + 9*\dfrac{49}{4} +\dfrac{49*85}{16}\right)\\\\=2*\left(765 +110.25 + 260.3125 \right)\\\\= 2 *1135.56\\\\= 2271.12 \ in^2[/tex]
