Please answer this correctly

 1 km by 5 km

Step-by-step explanation:

Perimeter of green = 2(4) + 2(2)

                                =  8    +   4

                                = 12

Let the width of the yellow = w

and the length of the yellow = L

Then Perimeter = 2w + 2L      Perimeter of yellow = Perimeter of green

                    12 = 2w + 2L    

Solve for one of the variables (I chose to solve for w)

                  12 - 2L = 2w

                   6 - L = w

Area = length × width     Area is given as 5

Substitute "w" with 6 - L

5 = L(6 - L)

5 = 6L - L²

L² - 6L + 5 = 0

(L - 1) (L - 5) = 0

L = 1    L = 5

Both answers are positive so both are valid.

Now, solve for w = 6 - L

                         w = 6 - 1          w = 6 - 5

                             =  5                  =  1

The measurements are the same (1 × 5), depending on which sides you choose to be the width and the Length.

width = 1, Length = 5    or     width = 5, Length = 1