Mark H. answered 05/29/19
Tutoring in Math and Science at all levels
Suppose the length is exactly 2 times the width.
The perimeter is 2W + 2L = 70
But L = 2W, so we can substitute L for the 2W:
L + 2L = 70
3L = 70, and L = 70/3
And W = L/2 = 35/3
Now, what happens when L gets smaller? Using the first equation, a smaller L simply means that W is larger---this continues for all values of L down to 0. There is no unique answer---perhaps there is an error in how the problem is stated?