Answer
The answer is 10 inches in length and 20 inches in width.
Work Step by Step
We assign the variables:
$l=$ length of the rectangle
$w=$ width of the rectangle
Step 1:
Find the equations that represent the problem:
The formula for the perimeter of a rectangle is
$P=2l+2w$ -> Eq. 1
We can the second equation from the wording in the problem.
From "Is twice as long as it is wide", we get:
$w=2l$ -> Eq. 2
Step 2:
Solve the system of equations. Using the substitution method,
-> Substitute Eq. 2 into Eq. 1
$w+2w=60$
$3w=60$
$w=\frac{60}{3}$
$w=20$ $in$
->Substitute the value for w into Eq. 2
$2l=20$
$l=\frac{20}{2}$
$l=10$ $in$
Step 3:
The answer is 10 inches in length and 20 inches in width.
