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OBM 2005 Problem 5

    Let ABCABC be a triangle with all angles ≤120∘\leq 120^{\circ}. Let FF be the Fermat point of triangle ABCABC, that is, the interior point of ABCABC such that ∠AFB=∠BFC=∠CFA=120∘\angle AFB = \angle BFC = \angle CFA = 120^\circ. For each one of the three triangles BFCBFC, CFACFA and AFBAFB, draw its Euler line - that is, the line connecting its circumcenter and its centroid.

    Prove that these three Euler lines pass through one common point.

    Remark. The Fermat point FF is also known as the first Fermat point or the first Toricelli point of triangle ABCABC.

    Floor van Lamoen

    Dataset text AoPS wiki problems. Quoted with source.

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