Problem

Source:

Tags: geometry



Jia Herng has a circle $\omega$ with center $O$, and $P$ is a point outside of $\omega$. Let $PX$ and $PY$ are two lines tangent to $\omega$ at $X$ and $Y$ , and $Q$ is a point on segment $PX$. Let $R$ is a point on the ray $PY$ beyond $Y$ such that $QX = RY$. Help Jia Herng prove that the points $O$, $P$, $Q$, $R$ are concyclic.