Question

The length of a rectangle is twice it’s width.The perimeter of the rectangle in 162 inches.How long is the rectangle?

Answer 1

The perimeter of a rectangle is all sides added  up, so length + length + width + width.

L = length

W = width

then the perimeter is L+L+W+W, or 2L + 2W, or 2(L+W).

$\bf \textit{perimeter of a rectangle}\\\\ P=2(L+W)~~ \begin{cases} P=162\\ L=\stackrel{\textit{twice W}}{2W} \end{cases}\implies 162=2(2W+W) \\\\\\ \cfrac{162}{2}=3W\implies 81=3W\implies \cfrac{81}{3}=W\implies 27=W$

what's the length?  well, is just 2(27).