Answer:
See below.
Step-by-step explanation:
You didn't provide any dimensions to test the answers with, but here is how you could solve the problem.
A rectangular prism is just an oblong cardboard box basically. Think about how you would unfold that box. It would be made up of 3 pairs of rectangles (2 end pieces, the top and bottom, and 2 sides). To calculate its surface area you just calculate the areas of each piece and add them up.
The overall formula ends up being:
Area = 2(LW) + 2(LH) + 2(WH)
