Respuesta :

The formula for area is A = bh
B = Length
H = Width

If B is 5 times longer than H...

A = 5x(x)

Now let's solve

20000 = 5(x)(x)
20000 = 5x^2
   /5          /5
  4000 = x^2
    *square*
      20 = x

The height (width) is 20. (x)
The base (length) is 100 (5x -> 5(20) -> 100)

Proof: 20 times 100 = 20000