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CONO-SUR 2010 Problem 5

    The incircle of triangle ABCABC touches sides BCBC , ACAC , and ABAB at D,ED, E , and FF respectively. Let ωa,ωb\omega_a, \omega_b and ωc\omega_c be the circumcircles of triangles EAF,DBFEAF, DBF , and DCEDCE , respectively. The lines DEDE and DFDF cut ωa\omega_a at Ea≠EE_a\neq{E} and Fa≠FF_a\neq{F} , respectively. Let rAr_A be the line EaFaE_{a}F_a . Let rBr_B and rCr_C be defined analogously. Show that the lines rAr_A , rBr_B , and rCr_C determine a triangle with its vertices on the sides of triangle ABCABC .

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