For the truss shown in figure, the magnitude of the force in member PR and the support reaction at R are respectively

1. $122.47$ $kN$ and $50$ $kN$
2. $70.71$ $kN$ and $100$ $kN$
3. $70.71$ $kN$ and $50$ $kN$
4. $81.65$ $kN$ and $100$ $kN$