Le,
boa noite!
Note que o raio da circunferência corresponde ao lado OA. Podemos encontrá-lo usando tangente de 30°, veja:
[tex]\tan30^0=\frac{\text{cat. op.}}{\text{cat. adj.}}\\\\\\\frac{\sqrt{3}}{2}=\frac{\overline{OA}}{\overline{PA}}\\\\\\\frac{\sqrt{3}}{3}=\frac{r}{9}\\\\3r=9\sqrt{3}\\\\\boxed{r=3\sqrt{3}}[/tex]
Portanto,
[tex]C=2\pi r\\\\C=2\cdot3,14\cdot3\sqrt{3}\\\\C=18,84\cdot\sqrt{3}\\\\C=18,84\cdot1,7\\\\\boxed{\boxed{C=32,028\;\text{cm}}}[/tex]
