MathDB
CNCM Online R1P6

Source:

September 2, 2020

Problem Statement

In triangle ABC\triangle ABC with BC=1BC = 1, the internal angle bisector of A\angle A intersects BCBC at DD. MM is taken to be the midpoint of BCBC. Point EE is chosen on the boundary of ABC\triangle ABC such that MEME bisects its perimeter. The circumcircle ω\omega of DEC\triangle DEC is taken, and the second intersection of ADAD and ω\omega is KK, as well as the second intersection of MEME and ω\omega being LL. If BB lies on line KLKL and EDED is parallel to ABAB, then the perimeter of ABC\triangle ABC can be written as a real number SS. Compute 1000S\lfloor 1000S\rfloor.
Proposed by Albert Wang (awang11)