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Napoleon-Feuerbach Cubic


NapoleonFeuerbachCubic

The Napoleon-Feuerbach cubic is the pivotal isogonal cubic with nine-point center N as the pivot point. It therefore has trilinear equation

 (alpha^2-beta^2)gammacos(A-B)+beta(gamma^2-alpha^2)cos(A-C) 
 +alpha(beta^2-gamma^2)cos(B-C)=0.

It passes through Kimberling centers X_i for i=1 (incenter I), 3 (circumcenter O), 4 (orthocenter H), 5 (nine-point center N), 17 (first Napoleon point), 18 (second Napoleon point), 54 (Kosnita point), 61, 62, 195, 627, 628, 2120, 2121, as well as the excenters J_A, J_B, and J_C.


See also

Pivotal Isogonal Cubic, Triangle Cubic

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References

Čerin, Z. "On the Cubic of Napoleon." J. Geom. 66, 55-71, 1999.Gibert, B. "Napoleon-Feuerbach Cubic." http://perso.wanadoo.fr/bernard.gibert/Exemples/k005.html.

Referenced on Wolfram|Alpha

Napoleon-Feuerbach Cubic

Cite this as:

Weisstein, Eric W. "Napoleon-Feuerbach Cubic." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Napoleon-FeuerbachCubic.html

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