MathDB

(067) T1

Part of 1984 Tournament Of Towns

Problems(1)

TOT 067 1984 Autumn Train J1 <A =60^o or ABC is isosceles

Source:

8/24/2019
In triangle ABCABC the bisector of the angle at BB meets ACAC at DD and the bisector of the angle at CC meets ABAB at EE. These bisectors intersect at OO and the lengths of ODOD and OEOE are equal. Prove that either ∠BAC=60o\angle BAC = 60^o or triangle ABCABC is isosceles.
geometryangle bisectorisosceles