Vertex

Pronunciation: /ˈvɜrtɛks/ ?

A vertex is a point that is the endpoint of two or more non-collinear line segments or rays.^[1][2] The plural of vertex is vertices.

Examples of Vertices

Diagram	Description
Figure 1: Vertex of an angle.	The vertex of an angle is the point where the lines intersect that form the angle.
Figure 2: Vertices of a triangle.	The vertices of a triangle are the points where the sides of the triangle intersect.
Figure 3: Vertices of a polygon.	The vertices of a polygon are the points where the sides of the polygon intersect.
Figure 4: Vertices of parabolas.	A vertex is also the inflection point of a parabola or a polynomial. This is the point where the curve changes direction.

References

1. vertex. http://wordnet.princeton.edu/. WordNet. Princeton University. (Accessed: 2011-01-08). http://wordnetweb.princeton.edu/perl/webwn?s=vertex&sub=Search+WordNet&o2=&o0=1&o7=&o5=&o1=1&o6=&o4=&o3=&h=.
2. Keller, Samuel Smith. Mathematics for Engineering Students, Plane and Solid Geometry. D. Van Nostrand Company, 1908. (Accessed: 2010-01-02). http://www.archive.org/stream/mathengineer00kellrich#page/1/mode/1up/search/vertex.
3. Casey, John, LL.D., F.R.S.. The First Six Books of the Elements of Euclid, pg 7. Casey, John, LL.D. F.R.S.. Hodges, Figgis & Co., 1890. (Accessed: 2010-01-02). http://www.archive.org/stream/firstsixbooksofe00caseuoft#page/7/mode/1up/search/vertex.

Cite this article as:

Vertex. 2010-01-01. All Math Words Encyclopedia. Life is a Story Problem.org. http://www.allmathwords.org/en/v/vertex.html.

Translations

• Chasque para ver este artículo en español.

Image Credits

• All images and manipulatives are by David McAdams unless otherwise stated. All images by David McAdams are Copyright © Life is a Story Problem.org and are licensed under the Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.

Revision History

2010-01-07: Added "References" (McAdams, David.)
2008-10-11: Added vertex of a polynomial (McAdams, David.)
2008-06-07: Corrected spelling (McAdams, David.)
2008-04-23: Initial version (McAdams, David.)