A moves on major arc BC and some point is on the same distance from BC
Source: 2021 Oral Moscow Geometry Olympiad grades 10-11 p3
May 17, 2021
geometryangle bisectorcircumcircle
Problem Statement
Circle and its chord are given. Point moves on the major arc . is the angle bisector in a triangle . Show that the disctance from the circumcenter of triangle to the line does not depend on the position of point .