P=2(L+W)
if L is 6 great than W
L=6+W
and P=40
subsitute 40 for P and 6+W for l
40=2(6+W+W)
40=2(6+2W)
divide both sides by 2
20=6+2W
minus 6 both sides
14=2W
divide both sides by 2
7=W
W=7
sub back
L=6+W
L=6+7
L=13
the rectangle has a length of 13ft and width of 7ft
