MathNet 2026 — Part 07 Question 11

Let $ABCD$ be a convex quadrilateral such that $\widehat{CAB} = \widehat{CDA}$ and $\widehat{BCA} = \widehat{ACD}$. Said $M$ the midpoint of $AB$ proves that $\widehat{BCM} = \widehat{DBA}$.