The Surface Area of a Rectangular Box
The more formal name for a rectangular box is a rectangular prism. To find the surface area of a rectangular prism, you need to find the area of each face and then add those areas together. Here is an example.
The rectangular prism’s height is 1 cm, length is 2 cm, and depth is 3 cm. Here is the net of this box:
Notice how each side is labeled in centimeters, and each area is labeled in centimeters squared.
Let’s add the area of each face together:
6 cm2 + 3 cm2 + 6 cm2 + 3 cm2 + 2 cm2 + 2 cm2 = 22 cm2
Did you notice that there are pairs of faces with the same area? That’s because the front and back are the same, the top and bottom are the same, and the two sides match as well.