Let l = the length of the rectangle
let w= the width of the rectangle
"The length of a rectangle is twice its width" can be written as;
l = 2w
Perimeter of a rectangle = 2l + 2w
If the perimeter of the recatngle is 140 feet
Then this implies;
2l + 2w = 140 -------------------------------- (1)
But l=2w
substituting l = 2w in equation 1
2(2w) + 2w = 140
or we can also say
2l + l = 140
