Question 30
Let $\omega_{1}$ and $\omega_{2}$ two center circles $O_{1}$ and $O_{2}$, assume that they are cut in $A$ and $B$. The circle passing through the points $O_{1}$, $O_{2}$ and $B$ cuts the circle $\omega_{1}$ in $C$. Show that points $C$, $A$ and $O_{2}$ are aligned. 