MathDB
2014 JBMO Shortlist G1

Source: 2014 JBMO Shortlist G1

October 8, 2017
JBMOgeometry

Problem Statement

Let ABC{ABC} be a triangle with m(B)=m(C)=40m\left( \angle B \right)=m\left( \angle C \right)={{40}^{{}^\circ }} Line bisector of B{\angle{B}} intersects AC{AC} at point D{D}. Prove that BD+DA=BCBD+DA=BC.