MathDB
perpendicular segments

Source: Balkan MO 2014 G-5

June 10, 2015
geometrytrapezoid

Problem Statement

Let ABCDABCD be a trapezium inscribed in a circle kk with diameter ABAB. A circle with center BB and radius BEBE,where EE is the intersection point of the diagonals ACAC and BDBD meets kk at points KK and LL. If the line ,perpendicular to BDBD at EE,intersects CDCD at MM,prove that KMDLKM\perp DL.