MathDB
concurrency of perp. bisectors (2020 Kyiv City MO 7.4.1)

Source:

September 19, 2020
geometryconcurrencyconcurrentperpendicular bisectorequal segments

Problem Statement

In the quadrilateral ABCDABCD, AB=BCAB = BC . The point EE lies on the line ABAB is such that BD=BEBD= BE and ADDEAD \perp DE. Prove that the perpendicular bisectors to segments AD,CDAD, CD and CECE intersect at one point.