Encyclopedia of Triangle Centers
The Encyclopedia of Triangle Centers (ETC) is an online list of over 30,000 (December 2018) triangle points . It is maintained by Clark Kimberling , Professor of Mathematics at the University of Evansville.
Each entry in the list is assigned a so-called Kimberling number in the form X (n). The information about each point includes its trilinear and barycentric coordinates as well as its position in relation to straight lines that connect other identified points. The ETC also offers a glossary of terms and definitions.
In 1998, Kimberling published the 400 most important triangle points of the online encyclopedia in book form under the title Triangle Centers and Central Triangles .
List of some triangle points with Kimberling numbers
| Surname | number |
|---|---|
| Inscribed center | X (1) |
| main emphasis | X (2) |
| Circumcenter | X (3) |
| Intersection point (orthocenter) | X (4) |
| Center of the Feuerbach circle | X (5) |
| Lemoine point (symmetry point, Grebe point) | X (6) |
| Gergonne point | X (7) |
| Nail point | X (8) |
| Midpoint | X (9) |
| Spieker Point (Spieker Center) | X (10) |
| 1. Fermat point | X (13) |
| 2. Fermat point | X (14) |
| 1st isodynamic point | X (15) |
| 2nd isodynamic point | X (16) |
| 1. Napoleon point | X (17) |
| 2. Napoleon point | X (18) |
| Clawson point | X (19) |
| Longchamps point | X (20) |
| Schiffler point | X (21) |
| Exeter point | X (22) |
| Bevan point | X (40) |
| Kosnita point | X (54) |
| Tarry point | X (98) |
| Steiner point | X (99) |
| Isoperimetric point | X (175) |
| 1. Vecten point | X (485) |
| 2. Vecten point | X (486) |