Question 721997
We let the length be 4x

Let the width be x

So, 4x*x = 1600 cm^2

So, 4x^2 = 1600

So, x^2 = 400 and x=20

Therefore, plugging them into the previous lengths we get,

4x = 80

x = 20

So the dimensions are 80 x 20.

And 80 x 20 = 1600, which works