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equal segments wanted, symmetric point , <A=60 given

Source: II Brazilian Olympic Revenge 2003 p3

April 22, 2020
geometrySymmetricequal segments

Problem Statement

Let ABCABC be a triangle with BAC=60\angle BAC =60^\circ. AA' is the symmetric point of AA wrt BC\overline{BC}. DD is the point in AC\overline{AC} such that AB=AD\overline{AB}=\overline{AD}. HH is the orthocenter of triangle ABCABC. ll is the external angle bisector of BAC\angle BAC. {M}=ADl\{M\}=\overline{A'D}\cap l,{N}=CHl\{N\}=\overline{CH} \cap l. Show that AM=AN\overline{AM}=\overline{AN}.