Find the length, width, and height of the rectangular prism.
Calculate the area of each pair of opposite faces:
Front and back: length × height
Top and bottom: length × width
Left and right: width × height
Add the areas of all six faces:
Surface area = 2(length × width) + 2(length × height) + 2(width × height)
Use the formula to get the total area of the rectangular prism.