You want the area of the platform in the tree house to be 12/5 sq yd. If the length of the platform is 4/3 yd, then the width of the platform is
Area of the tree house = 125 sq yd.
Length = 43 yd
We know, Area = Length×Width
∴ Width = AreaLength
=125÷43
=125×34
=95 yd