Answer:
width=71km, length=177.5km
Explanation:
Let x be the width of the farm.
Then the length of the farm will be 2.5x.
perimeter of farm in terms of x=2.5x+2.5x+x+x=7x
perimeter of farm in terms of x=perimeter of farm
7x=497
x=71
width=71km
length=71×2.5=177.5