MathDB
midpoint wanted, concurrent cevians given (Kyiv City Olympiad 2008 10.4)

Source:

June 30, 2020
geometrymidpointCevians

Problem Statement

Given a triangle ABCABC , AA1A {{A} _ {1}} , BB1B {{B} _ {1}} , CC1C {{C} _ {1}} - its chevians intersecting at one point. A0,C0{{A} _ {0}}, {{C} _ {0}} - the midpoint of the sides BCBC and ABAB respectively. Lines B1C1{{B} _ {1}} {{C} _ {1}} , B1A1{{B} _ {1}} {{A} _ {1}} and B1B{ {B} _ {1}} B intersect the line A0C0{{A} _ {0}} {{C} _ {0}} at points C2{{C} _ {2}} , A2{{A} _ {2}} and B2{{B} _ {2}} , respectively. Prove that the point B2{{B} _ {2}} is the midpoint of the segment A2C2{{A} _ {2}} {{C} _ {2}} .
(Eugene Bilokopitov)