Question 757426
Perimeter = 2*length + 2*width
Perimeter = 2*(x + 40) + 2x
200yds    = 2x + 80 + 2x
      4x + 80 = 200
            4x = 200 - 80
            4x = 120
             x = 30.
Length = 70yds
Width = 30yds
Perimeter = 2*length + 2*width
          = 2*70 + 2*30
          = 200yds.
Hope this helps.
:-)