If you're unsure of a term, click Glossary or Pierre Douillet's much expanded and very useful version: To determine if a possibly new center is already listed, click Tables at the top of this page and scroll to "Search 6.9.13". Other named centers can be found using your computer's searcher - for example, search for "Apollonius" to find "Apollonius point" as X(181). You won't have to scroll down very far to find well known centers. Special points and properties of 4-sided plane figures are closely associated with triangle centers see Chris van Tienhoven's In particular, Eric Weisstein'sĬovers much of classical and modern triangle geometry, including sketches and references.Ī site in which triangle centers play a central role is Bernard Gibert's The Encyclopedia of Triangle Centers (ETC) extends a list of 400 triangle centers published in the 1998 bookįor subsequent developments, click Links (one of the buttons atop this page). Like the definition of continuous function, this definition is satisfied by infinitely many objects, of which only finitely many will ever be published. More centuries passed, more special points were discovered, and a definition of The ancients found other points, too, now called the incenter, Word spread, and the magic of the three segments was regarded as the work of a higher power.Ĭenturies passed, and someone proved that the three medians do indeed concur in a point, now called the
![gsp5 construct circumcenter gsp5 construct circumcenter](http://jwilson.coe.uga.edu/EMT668/EMAT6680.2002.Fall/Ledford/ledford4/images4/image11.gif)
To their surprise and delight, the coincidence worked for them, too. The person drew yet a third triangle, very carefully, with the same result.
![gsp5 construct circumcenter gsp5 construct circumcenter](http://i.ytimg.com/vi/7W9B6DFVdOY/0.jpg)
![gsp5 construct circumcenter gsp5 construct circumcenter](https://i.pinimg.com/474x/1a/56/d1/1a56d1e985c37ba20d90f062a0af0b21.jpg)
The person was impressed and repeated the experiment on a different shape of triangle. Each segment started at a vertex and stopped at the midpoint of the opposite side. Long ago, someone drew a triangle and three segments across it. This is PART 1: Introduction and Centers X(1) - X(1000) PART 1: