[tex]\textit{arc's length}\\\\ s=\cfrac{r\theta \pi }{180}~~ \begin{cases} r=radius\\ \theta =\stackrel{degrees}{angle}\\[-0.5em] \hrulefill\\ r=6\\ \theta =128 \end{cases}\implies s=\cfrac{(6)\pi (128)}{180}\implies s=\cfrac{64\pi }{15}\implies s\approx 13.4[/tex]
