[tex]\bf \textit{arc's length}\\\\ s=r\theta ~~ \begin{cases} r=radius\\ \theta =angle~in\\ \qquad radians\\ \cline{1-1} r=6\\ \theta =\frac{2\pi }{5} \end{cases}\implies s=6\cdot \cfrac{2\pi }{5}\implies s=\cfrac{12\pi }{5}\implies s\approx 7.54[/tex]
