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MathNet 2016-part-04 — 184 problems (EN–VI) Question 128

Math Olympiad Vault · MathNet 2016-part-04 — 184 problems (EN–VI)

Question 128

Let $ABCD$ be a trapezoid with $BC \parallel AD$ and $AB = CD$. A circle $\omega$ centered at $I$ is tangent to the segments $AB$, $CD$, and $DA$. The circle $BIC$ meets the side $AB$ at points $B$ and $E$. Prove that $CE$ is tangent to $\omega$.