Question 140
From point $P$ outside a circle draw two tangents to the circle touching at points $A$ and $B$. Draw a secant line intersecting the circle at points $C$ and $D$, with $C$ between $P$ and $D$. Choose point $Q$ on the chord $CD$ such that $\angle DAQ = \angle PBC$. Prove that $\angle DBQ = \angle PAC$.