Respuesta :

[tex]\bf \textit{arc's length}\\\\ s=r\theta \quad \begin{cases} r=radius\\ \theta =angle~in\\ \qquad radians\\ ------\\ r=25\\ \theta =\frac{7\pi }{5} \end{cases}\implies s=25\cdot \frac{7\pi }{5}\implies s=35\pi [/tex]