Answer:
length: 90 ft
width: 30 ft
Step-by-step explanation:
The sum of length and width is half the perimeter, so is 120 ft. The length is 3/(3+1) = 3/4 of the sum, so is (3/4)(120 ft) = 90 ft. The width is 120 ft -90 ft = 30 ft.
The floor has a length of 90 feet and a width of 30 feet.
