Digital PSAT Math Practice Question 211: Answer and Explanation

Question: 211

What is the surface area in square units of a right rectangular prism with edges of 2, 3, and 4 units?

Correct Answer: 52

Explanation:

(52) Each of the six faces of a right rectangular prism (a box) is a rectangle-you can calculate the area of a rectangle by multiplying its length by its width. So, for a right rectangular prism with edges of x, y, and z units, the surface area can be calculated as follows:

2xy + 2xz + 2yz

Plug in 2 for x, 3 for y, and 4 for z to calculate the total surface area:

2(2)(3) + 2(2)(4) + 2(3)(4) = 12 + 16 + 24 = 52 square units