MathDB
JBMO TST 2020 - Moldova P11

Source: JBMO TST 2020 Moldova

October 13, 2020
geometrycircumcircle

Problem Statement

Let ABC\triangle ABC be an acute triangle. The bisector of ACB\angle ACB intersects side ABAB in DD. The circumcircle of triangle ADCADC intersects side BCBC in CC and EE with CEC \neq E. The line parallel to AEAE which passes through BB intersects line CDCD in FF. Prove that the triangle AFB\triangle AFB is isosceles.