(1998 KJMO P7) ADE is an isosceles triangle
Source: 1998 KJMO P7
June 30, 2024
geometrycircumcircleangle bisectorKJMO
Problem Statement
is a circumcircle of non-isosceles triangle and the angle bisector of meets at . If the line perpendicular to passing through meets at , show that is an isosceles triangle.