Question

A rectangular prism has a height of 15 centimeters and a width of 6 centimeters. The surface area of the prism is 684 square centimeters. What is the length of the prism?

A. 24 cm

B. 12 cm

C. 9 cm

D. 6 cm

Answer 1

Explanation:

Let the length be L

Formula

SA = 2Lw + 2Lh + 2wh

Givens

h = 15 cm

w = 6 cm

L = ?

SA = 684 cm^2

Solution

Substitue what you know into the given formula

2*6*L + 2*15*L + 2 * 6 * 15 = 684 Combine

12*L + 30*L + 180 = 684 Combine again

42L + 180 = 684 Subtract 180 from both sides.

42L +180 -180 = 684 - 180

42L = 504 Divide by 42

Answer: L = 12