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SMO 2008 Open Round 1 Question 9

SMO · SMO 2008 Open Round 1

Question 9

In a convex quadrilateral $ABCD$, $\angle BAC=\angle CAD$ and $\angle ABC=\angle ACD$. The extensions of $AD$ and $BC$ meet at $E$, and the extensions of $AB$ and $DC$ meet at $F$. Determine $\dfrac{AB\cdot DE}{BC\cdot CE}$.