Euler Line

Pronunciation: /ˈɔɪ.lər laɪn/ Explain

Click on the blue points and drag them to change the figure.

Of the three points, which are always inside the triangle?
Manipulative 1 - Euler Line Created with GeoGebra.

An Euler line is a line that passes through the orthocenter, centroid, and circumcenter of a triangle.[1] In manipulative 1, the Euler line is the red line.

The Euler line was first described by Leonhard Euler in Novi Commentarii academiae scientarum imperialis Petropolitanae 11: 103–123. Since the introduction of the Euler line, many other triangle centers have been found that are on the Euler line, including the center of the 9 point circle.


  1. McAdams, David E.. All Math Words Dictionary, euler line. 2nd Classroom edition 20150108-4799968. pg 73. Life is a Story Problem LLC. January 8, 2015. Buy the book
  2. Leonard Eulero. Sovtio Facilis Problematum Quorumdam Geometricorum Difficilimorum. 11: 103–123. Novi Commentarii academiae scientarum imperialis Petropolitanae. Last Accessed 7/9/2018.
  3. Mackay, J. S.. The Triangle and its Six Scribed Circles. pp 97-103. Proceedings of the Edinburgh Mathematical Society, Volume 1. Edinburgh Mathematical Society. 1883. Last Accessed 7/9/2018.
  4. Coxeter, H.M.S. and Greitzer, S.L.. Geometry Revisited. 1st edition. pp 18-20. The Mathematical Association of America. 1967. Last Accessed 7/9/2018. Buy the book

More Information

  • Kimberling, Clark. Euler Line. 1/29/2010.

Cite this article as:

McAdams, David E. Euler Line. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC.

Image Credits

Revision History

12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
7/5/2018: Removed broken links, updated license, implemented new markup, implemented new Geogebra protocol. (McAdams, David E.)
1/29/2010: Added "References". (McAdams, David E.)
1/5/2009: Initial version. (McAdams, David E.)

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