A rectangle has a perimeter of 72 feet. The length is twice the width. Find the dimensions of the rectangle ...

Set up a system of equations:

2l + 2w = 72

l = 2w

Solve the system using substitution:

2 (2w) + 2w = 72

Solve for w:

4w + 2w = 72

-> 6w = 72

-> w = 12

Plug in the value for 'w' in the second equation:

l = 2 (12)

-> l = 24

The width is 12.

The length is 24.