Answer:
20 cm^2
Explanation:
First, you want to find the area of the entire rectangle.
It would be base*height, or 9*3=27 cm^2
Then, you can subtract the area of the half-circle.
Its radius is 1.5 cm.
So, it would be 2.25pi, or about 7cm^2.
Then, you could do 27-7 to get 20 cm^2 as the area