Actually Welcome to the Concept of the areas.
Let the length be x and width be y, hence we get the relation as,
2(l+b) = perimeter, here l=x and b =y
2(x+y) = 2 feet, but since y = 2/3x
so we get as,
2(x+(2/3)*x)= 2 ft
===> 2x + (4/3)*x = 2 ft
===> taking the lcm
===> 6x + 4x = 6 ft
===> x = 6/10 = 0.6 ft
so x = 0.6 ft and y = (2/3)*(6/10) = 2/5 ft
hence, x = 3/5 feet and y = 2/5 feet