MathDB

2016.8.5

Part of Kyiv City MO Juniors 2003+ geometry

Problems(1)

<ACB=60 iffAE + BD = AB, angle bisectors (2016 Kyiv City MO 8.5)

Source:

9/5/2020
In the triangle ABCABC the angle bisectors ADAD and BEBE are drawn. Prove that ∠ACB=60∘\angle ACB = 60 {} ^ \circ if and only if AE+BD=ABAE + BD = AB.
(Hilko Danilo)
geometryangle bisectorangles