Polish MO 2022 P2
Source: Polish MO 2022 P2
February 12, 2022
geometrycircumcircleperpendicular
Problem Statement
Given a cyclic quadriteral . The circumcenter lies in the quadriteral . Diagonals and intersects at . Points and are the midpoints of and . Let be a line perpendicular to through , perpendicular line to through and perpendicular to through . Prove that intersects at one point.