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Geometry Mathley 14.2 angle bisector related to Euler Circle

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June 7, 2020
Euler Circletangent circlesangle bisectorgeometryEuler

Problem Statement

The nine-point Euler circle of triangle ABCABC is tangent to the excircles in the angle A,B,CA,B,C at Fa,Fb,FcFa, Fb, Fc respectively. Prove that AFaAF_a bisects the angle CAB\angle CAB if and only if AFaAFa bisects the angle FbAFc\angle F_bAF_c.
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