Answer: length = 72 feet
Width = 48 feet
Explanation:
Let L represent the length of the rectangular garden.
Let W represent the width of the rectangular garden.
The width is exactly two-thirds of the length. It means that
W = 2L/3
If 240 feet of antique picket fencing are to be used to enclose the garden, it means that the perimeter of the rectangular field is 240 feet. The perimeter of the rectangular field is expressed as
2(L+W). Therefore,
2( L+ W) = 240
L+ B = 120
Substituting W = 2L/3 into L+ B = 120, it becomes
L + 2L/3 = 120
3L + 2L = 360
5L = 360
L = 360/5 = 72 feet
W = 2L/3
W = 2×72/3 = 144/3
W = 48 feet