Answer:
1 sq.unit = 9 sq.feet
Explanation:
Length of shaded rectangle = 6 square on grid
We are given that Each square on the grid has a length of 1 unit.
So, Length of shaded rectangle = 6 units
Breadth of shaded rectangle = 4 square on grid = 4 units
Area of shaded rectangle =

We are given that area of original square = 288 sq.feet
32 sq.unit = 288 sq.feet
1 sq.unit =

So, 1 sq.unit = 9 sq.feet
Hence Scale is 1 sq.unit = 9 sq.feet