Answer:
- length: 485 ft
- width: 85 ft
Step-by-step explanation:
Let the length be represented by L. Then the width is L-400, and the perimeter is ...
P = 2(L +W)
1140 = 2(L +(L-400))
570 = 2L -400 . . . . . . . divide by 2
970 = 2L . . . . . . . . . . . . add 400
485 = L . . . . . . . . . . . . . divide by 2
L-400 = 485-400 = 85 . . . . . find the width
The length is 485 ft; the width is 85 ft.
