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ortocenters of BCK,ACN coincide iff BN/AK =/tan^2 A, right ABC

Source: 2016 XIX All-Ukrainian Tournament of Young Mathematicians named after M. Y. Yadrenko, Qualifying p1

May 6, 2021
geometryorthocenterright triangleUkrainian TYM

Problem Statement

The points KK and NN lie on the hypotenuse ABAB of a right triangle ABCABC. Prove that orthocenters the triangles BCKBCK and ACNACN coincide if and only if BNAK=tan2A.\frac{BN}{AK}=\tan^2 A.