perimeter = 2L +2W, divide total perimeter by 2 for total length of 1 side and 1 width
172/2 = 86 ( total for 1 side and 1 width)
86-24 = 62 (since length is 24 ft longer subtract 24 then divide by 2 for width)
62/2 = 31
width = 31 feet
length = 31 +24 = 55 feet
check: 31*2 = 62, 55*2 = 110, 110+62 = 172