Respuesta :

Answer:

9 pi

Step-by-step explanation:

First find the circumference of the circle

C =2 * pi *r

C = 2 * pi *9

C = 18 pi

This is a semicircle which is 1/2 of a circle

Take 1/2 of the circumference

1/2 C = 1/2 ( 18 pi)

1/2 C = 9 pi