10π3 cm\frac{10 \pi}{3} \mathrm{~cm}310π cm
5π3 cm\frac{5 \pi}{3} \mathrm{~cm}35π cm
5π6 cm\frac{5 \pi}{6} \mathrm{~cm}65π cm
15πcm\frac{15}{\pi} \mathrm{cm}π15cm