Google Classroom
GeoGebraGeoGebra Classroom

The Feuerbach Hyperbola

The Feuerbach hyperbola is the isogonal conjugate of the line through the incenter (I) and the circumcenter (O). The center of the hyperbola is the Feuerbach point, the point of tangency between the nine-point circle and the incircle. The line IO is tangent to the hyperbola at I.