Let angle be alpha
[tex]\\ \rm\Rrightarrow Area=50.24[/tex]
[tex]\\ \rm\Rrightarrow \dfrac{\alpha}{360}\pi r^2=50.24[/tex]
[tex]\\ \rm\Rrightarrow \alpha 3.14r^2=18086.4[/tex]
[tex]\\ \rm\Rrightarrow \alpha r^2=5760[/tex]
[tex]\\ \rm\Rrightarrow r^2=\dfrac{5760}{\alpha}[/tex]
[tex]\\ \rm\Rrightarrow r=\sqrt{\dfrac{5760}{\alpha}}[/tex]
If you have angle measure in degree put in place of Alpha and get the value elaw this is our final answer