Question 121
Let quadrilateral $ABCD$ be inscribed in a circle. Let $E$ be the midpoint of arc $AB$ that does not contain $C$ or $D$, and let $F$ be the midpoint of arc $CD$ that does not contain $A$ or $B$. Let $AC \cap BF = K$, $BD \cap AF = L$, $AC \cap DE = M$, and $BD \cap CE = N$. Prove that $\angle DML = \angle CNK$.
(Khulan Tumenbayar)
(Khulan Tumenbayar)