Respuesta :
[tex]\bf \textit{arc's length}\\\\
s=\cfrac{\theta r\pi }{180}\quad
\begin{cases}
r=radius\\
\theta = angle~in\\
\qquad degrees\\
------\\
r=5\\
\theta = 42
\end{cases}\implies s=\cfrac{42\cdot 5\cdot \pi }{180}[/tex]