Question

If the width of a rectangle is 5 inches and its perimeter is 34 inches, find the length of the rectangle.The length of the rectangle is ___(Simplify your answer. Type an integer or a simplified fraction.)

Answer 1

The rule of the perimeter of the rectangle is

$P=2(L+W)$

L is the length

W is the width

Since the width of the rectangle is 5 inches

Since the perimeter of the rectangle is 34 inches, then

W = 5

P = 34

Substitute them in the rule above

$34=2(L+5)$

Divide both sides by 2

$\begin{gathered} \frac{34}{2}=\frac{2(L+5)}{2} \\ 17=L+5 \end{gathered}$

Subtract 5 from each side

$\begin{gathered} 17-5=L+5-5 \\ 12=L \end{gathered}$

The length of the rectangle is 12 inches