Answer:
[tex]28 . 26cm[/tex]
Step-by-step explanation:
First find the radius
[tex]d = 2r \\ 9 = 2r \\ \frac{9}{2} = \frac{2r}{2} \\ r = 4.5[/tex]
Now find the CIRCUMFERENCE
[tex]c = 2\pi \: r \\ = 2 \times \pi \times 4.5 \\ = 9 \times \pi \\ = 28.26[/tex]
