In quadrilateral $QRTS$, we have $QR = 11$, $QS = 9$, and $ST=2$. Sides $\overline{RQ}$ and $\overline{ST}$ are extended past $Q$ and $S$, respectively, to

$In quadrilateral $QRTS$, we have $QR = 11$, $QS = 9$, and $ST=2$. Sides $\overline{RQ}$ and $\overline{ST}$ are extended past $Q$ and $S$, respectively, to meet at point $P$. If $PS = 8$ and $PQ = 5$, then what is $RT$?$