MathDB
line passes through the circumenter

Source: IGO 2015 Intermediate 2

July 16, 2018
geometryreflectionmidpointscircumcircle

Problem Statement

In acute-angled triangle ABCABC, BHBH is the altitude of the vertex BB. The points DD and EE are midpoints of ABAB and ACAC respectively. Suppose that FF be the reflection of HH with respect to EDED. Prove that the line BFBF passes through circumcenter of ABCABC.
by Davood Vakili