MathDB
isosceles or <A = 60^o, because of angle bisectors

Source: Nordic Mathematical Contest 2000 #3

October 3, 2017
geometryisoscelesangle bisector

Problem Statement

In the triangle ABCABC, the bisector of angle ∠B\angle B meets ACAC at DD and the bisector of angle ∠C\angle C meets ABAB at EE. The bisectors meet each other at OO. Furthermore, OD=OEOD = OE. Prove that either ABCABC is isosceles or ∠BAC=60∘\angle BAC = 60^\circ.
Back to ProblemsView on AoPS