We will have the following:
First,:
[tex]\frac{4\pi}{15}=\frac{4\pi}{15}\ast\frac{180}{\pi}=48[/tex]Then, the arc length will be:
[tex]\begin{gathered} s=(\frac{15}{2})(\frac{4\pi}{15})\Rightarrow s=2\pi \\ \\ \Rightarrow s\approx6.3 \end{gathered}[/tex]So, the arc length is approximately 6.3 cm.