Answer
l=150 yd
w=75 yd
Work Step by Step
From the given description we know that l must equal 2w. Plug this value in for l in the perimeter equation and solve for w.
P=2l+2w
P=2(2w)+2w
450=2(2w)+2w
450=4w+2w
450=6w
$\frac{250}{6}$=w
75=w
w=75 yd
l=2w
l=2(75)
l=150 yd