Answer:
84ft
Explanation:
w = 2/3(L)
if 280 feet of fencing can enclose the garden,therefore the perimeter is 280 feet
perimeter = 2L + 2W
but W=2/3(L)
therefore, perimeter = 2L + 2(2/3L)
P= 2L + 4/3(L)
P= 10/3(L)
but P= 280
therefore 280= 10/3(L)
L = (3×280)÷10
L= 84 feet