The area of the green square is 9 ft2
. The area of the red square is 16 ft2
.
What is the area of the yellow square?
Since the green square has an area of 9 ft^2, we can determine that each side of the green square has a length of √9 = 3 ft.
Therefore, the yellow square has the same length as the sides of the green square.
Since the red square has an area of 16 ft^2, we can determine that each side of the red square has a length of √16 = 4 ft.
That means the yellow square has the same sides as the red square.
Therefore, the area of the yellow square is 4 ft * 4 ft = 16 ft^2. Answer: \boxed{16}.