Answer:
40 ft
Step-by-step explanation:
Data:
(1) P = 120 ft
(2) l = 2w
Calculations:
(3) P = 2l + 2w Substitute (1) and (2) into (3)
120 = 2(2w) + 2w Multiply
120 = 4w +2w Combine like terms
120 = 6w Divide by 6
(4) w = 20 ft Substitute (4) into (2)
l = 2 × 20
l = 40 ft
Check:
120 = 2×40 + 2×20
120 = 80 + 40
120 = 120