Answer:
l=102 feet, w=68 feet
Step-by-step explanation:
Let w=width and l=length
P=2l + 2w
And we know that w=2/3l
So, using substitution...
340=2l + 2(2/3l)
340=2l + 4/3l
340=6/3l + 4/3l
340=10/3l (now multiply both sides by 3 to get rid of fraction)
1020=10l
So l=102
Now plug in to get w
2(102)+2w=340
204+2w=340
2w=136
w=68
Now check:
2(102)+2(68)=
204+136=
340 It works!