Two Right Angles
In the figure above, $PQ=2\frac{1}{3}$, $PS = 6\frac{6}{7}$, $PQR$ and $PRS$ are right-angled triangles, and the angles $QPR$ and $RPS$ are the same.
How long is $PR$?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
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