102.14 A Note on the Feuerbach triangle

104.09 A harmonic range for the triangle

“…and the point . (2). It may also be shown that λ (1 + μν) 2 = −Π (1 − μν) + λ + 3Π, so the point lies between and on the Feuerbach line and also on the line joining the centroid and the Gergonne point .…”

“…may either be derived from first principles or translated from formulae given in terms of the sides , , ( [2]). It is then easy to show that the Feuerbach triangle and the reference triangle are in perspective with centre (perspector) .…”