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MathNet 2008-part-02 — 165 problems (EN–VI) Question 33

Math Olympiad Vault · MathNet 2008-part-02 — 165 problems (EN–VI)

Question 33

Let $ABC$ be a triangle and $D$, $E$, $F$ be points on the sides $BC$, $CA$, $AB$ respectively such that $AD = BE = CF$. Suppose the line segments $AD$, $BE$, $CF$ are not concurrent and enclose an equilateral triangle. Is $ABC$ necessarily equilateral?