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Euler line

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In any triangle \triangle ABC, the Euler line is a line which passes through the orthocenter H, centroid G, circumcenter O, nine-point center N and De Longchamps point L. It is named after Leonhard Euler. Its existence is a non-trivial fact of Euclidean geometry.

The Euler Line

Certain fixed orders and distance ratios hold among these points. In particular, \overline{OGNH} and OG:GN:NH = 2:1:3


Given the orthic triangle\triangle H_AH_BH_C of \triangle ABC, the Euler lines of \triangle AH_BH_C,\triangle BH_CH_A, and \triangle CH_AH_B concur at N, the nine-point center of \triangle ABC.


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