MathDB

9th XMO 2022 P2: Multi-center and a weird computation

Source: 9th XMO 2022

June 18, 2022

geometrycomputationChina

Problem Statement

Given a

\triangle ABC

with circumcenter

O

and orthocenter

H(O\ne H)

. Denote the midpoints of

BC, AC

D, E

and let

D', E'

be the reflections of

D, E

w.r.t. point

H

, respectively. If lines

AD'

and

BE'

meet at

K

, compute

\frac{KO}{KH}