Answer:
9π, or 28.26
Step-by-step explanation:
The Arc of the semicircle is the circumference of half a circle.
The radius of the semicircle is 9, and the circumference of a circle is 2πr, so it is 2π9 = 18π. since this is a semicircle, it is half of that, so 9π, or 28.26, since π is 3.14 here
