Word problem involving the surface area of a rectangular prism

In this lesson, we solve word problems involving the surface area of a rectangular prism.

A rectangular prism has a width of 10 cm, a height of 3 cm and a depth of 7 cm. What is the surface area of the prism?

Solution

Step 1:

Surface area of figure = 2 (l w + w h + l h) l = 7 cm; w = 10 cm; h = 3 cm

Step 2:

Surface area = 2(7 × 10 + 7 × 3 + 3 × 10)

= 242 square inches

What is the surface area of a figure that is 6 inches wide, 4 inches tall and 5 inches long?

Solution

Step 1:

Surface area of figure = 2 (l w + w h + l h) l = 5 in; w = 6 in; h = 4 in

Step 2:

Surface area = 2(5 × 6 + 5 × 4 + 6 × 4)

= 148 square inches