Answer:
113mm^2
Explanation:
Firstly work out the area of the pink circle using πr^2, which is the area of a process.
So we do πx12^2, which gives us 144π mm we have to divide this by two to get half of a circle hence giving us the area of the semi-circle. 72π mm is the area of the semicircle.
Then we must find the area of the white circle to subtract it from our semicircle. Since we know the radius is 12 from the center to anywhere, we know that the white circles diameter is 12, using our formula for the area all we need to do is πx6^2. This gives us 36π.
72π - 36π = 36π
36π is equal to 113.0973355 and since we need it too 3sf it will be 113mm^2