Question

the perimeter of a rectangle is 42 feet. the length of the rectangle is 12 feet. what is the width of the rectangle? a. 9 ft b. 12 ft c. 15 ft d. 30 ft

Explanation:

Step1: Recall perimeter formula

The perimeter formula for a rectangle is $P = 2(l + w)$, where $P$ is perimeter, $l$ is length and $w$ is width. Given $P = 42$ ft and $l=12$ ft.

Step2: Substitute values into formula

$42=2(12 + w)$. First, divide both sides of the equation by 2: $\frac{42}{2}=12 + w$, so $21 = 12+w$.

Step3: Solve for width

Subtract 12 from both sides: $w=21 - 12$, so $w = 9$ ft.

Answer:

A. 9 ft