Hey there!
In this problem, we'll just be finding the surface area of a rectangular prism. In this example, a surface area is a sum of all the areas of each individual face. On this rectangular prism, we have 6 faces, and two of each kind. Our formula is:
SA = 2(lw + wh + lh)
Notice how it has a 2. That two is because those two variables just applies for one side, and there's two for each type of side. On this diagram, the rightmost side's area would be the width (32) times the height (49) and the product would be the area. Let's plug in our numbers:
SA = 2(41 * 32 + 32*49 + 41*49)
Multiply:
SA = 2( 1312 + 1568 + 2009) =
Add:
SA = 2(2880 + 2009)
SA = 2(4889)
SA = 9778 ft squared, or C.
Hope this helps!