[tex]\text{Length of arc in (radian) = }\theta r[/tex][tex]L\text{ = }\pi cm,\text{ r=4cm}[/tex][tex]\begin{gathered} \pi\text{ = 4 x }\theta \\ \theta=\frac{\pi}{4} \\ \text{The angles measured in radian subtended by the arc is }\frac{\pi}{4} \end{gathered}[/tex]
