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MathNet 2019-part-07 — 184 problems (EN–VI) Question 61

Math Olympiad Vault · MathNet 2019-part-07 — 184 problems (EN–VI)

Question 61

In a triangle $ABC$, the interior angle bisector of $A$ intersects the $A$-excircle of $ABC$ at $D$ and $E$ such that $D \in [AE]$. Show that
$$
\frac{|AD|}{|AE|} \le \frac{|BC|^2}{|DE|^2}.
$$