INTERNATIONAL JOURNAL OF GEOMETRY Vol. 9 (2020), No. 1, 62 - 74 EXTREME POINTS ON CIRCUMCONICS INDUCED BY ISOGONAL CONJUGATES IN
INTERNATIONAL JOURNAL OF GEOMETRY Vol. 9 (2020), No. 1, 62 - 74 EXTREME POINTS ON CIRCUMCONICS INDUCED BY ISOGONAL CONJUGATES IN
![Let $A,B,C,D$ lie on a circle, $AD$ and $BC$ meet at $E$. The circle through $A,C,E$ have centre $O$. Prove that $BD$ is perpendicular to $EO$. - Mathematics Stack Exchange Let $A,B,C,D$ lie on a circle, $AD$ and $BC$ meet at $E$. The circle through $A,C,E$ have centre $O$. Prove that $BD$ is perpendicular to $EO$. - Mathematics Stack Exchange](https://i.stack.imgur.com/ibo9Q.jpg)