Since the perimeter us 66 ft and the length is 5 ft greater than the width, it can be said as:
66 ft = 5x ft + 5x ft + x ft + x ft
66 being perimeter, 5x being length, and x being width. This equation would then be simplified to:
66 ft = 10x ft + 2x ft
66 ft = 12x ft
Then using the simplified equation, you could then find x by dividing 66 by 12:
66 ft = 12x ft
5.5 ft = x ft
Using what has been found to be x, you would then just plug into the length and width equations:
5.5 ft = width
and
5 x 5.5 ft = 27.5 ft = length