Let
width,w
length, l = 1.6w ...eqn 1
area, a = l × w ...eqn 2
subst for l in eqn 2
a = 1.6 w × w = 4000
4000 = 1.6 w^2
w^2 = 2500
w = 50
subst for w in eqn 1
l = 50 x 1.6 = 80
length = 80 yds
width = 50 yds
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