Question

select the correct answer.
the perimeter of a rectangle is 42 inches. if the width of the rectangle is 6 inches, what is the length?
a. 12 inches
b. 15 inches
c. 21 inches
d. 40 inches

Explanation:

Step1: Recall rectangle perimeter formula

The perimeter of a rectangle is given by $P = 2(l + w)$, where $P$ is perimeter, $l$ is length, $w$ is width.

Step2: Substitute known values

Given $P = 42$ inches, $w = 6$ inches. Substitute into the formula:
$42 = 2(l + 6)$

Step3: Solve for $l$ (isolate the term)

Divide both sides by 2:
$\frac{42}{2} = l + 6$
$21 = l + 6$
Subtract 6 from both sides:
$l = 21 - 6$
$l = 15$

Answer:

B. 15 inches