Angelina A. answered 05/18/20
Physics and Math Tutor
For all of these equations:P is Perimeter, W is width, and L is length
First, we have to find the relationship between length and width which in this case it states:
L=2W
Now we know that a rectangle has 4 sides and the perimeter is all of the sides of the rectangle added up we know the equation would be:
P=W+W+L+L
Then we can plug in the equation from the first step into the second step because we know what L is :
P=W+W+2W+2W
Now we plug in the perimeter:
54 in=W+W+2W+2W
Now we can combine the W's in the equation:
54 in=6W
Now we can divide 6 by both sides to get the width equals 9 in. To get the length you plug it into the first equation L=2W
Then we figure out L=2(9in)
L=18 in
Finally, the dimensions are
Length=18 in
Width=9 in
Now if we want to check the answer we can just plug in all the numbers into the perimeter equation where:
P=W+W+L+L
P= 9 in +9in +18 in +18 in
P=54 in