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collinear wanted, AE = NE, CE = ME, rhombus related

Source: Oral Moscow Team MO 2017 IX p5 / All-Russian MO 1993 Regional (Round 4) 9.7

September 19, 2020
geometryrhombuscollinearequal segments

Problem Statement

On the diagonal ACAC of the rhombus ABCDABCD, a point EE is taken, which is different from points AA and CC, and on the lines ABAB and BCBC are points NN and MM, respectively, with AE=NEAE = NE and CE=MECE = ME. Let KK be the intersection point of lines AMAM and CNCN. Prove that points K,EK, E and DD are collinear.