A planar closed kinematic chain is formed with rigid links $PQ$ = $2.0$ $m$, $QR$ = $3.0$ $m$, $RS$ = $2.5$ $m$ and $SP$ = $2.7$ $m$ with all revolute joints. The link to be fixed to obtain a double rocker (rockerrocker) mechanism is
- $PQ$
- $QR$
- $RS$
- $SP$