Vertex
Pronunciation: /ˈvɜrtɛks/ Explain
A vertex is a point that is the endpoint of two
or more
noncollinear
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
 Keller, Samuel Smith. Mathematics for Engineering Students, Plane and Solid Geometry. www.archive.org. D. Van Nostrand Company. 1908. Last Accessed 1/2/2010. http://www.archive.org/stream/mathengineer00kellrich#page/1/mode/1up/search/vertex. Buy the book
 Casey, John, LL.D., F.R.S.. The First Six Books of the Elements of Euclid. pg 7. Translated by Casey, John, LL.D. F.R.S.. www.archive.org. Hodges, Figgis & Co.. 1890. Last Accessed 1/2/2010. http://www.archive.org/stream/firstsixbooksofe00caseuoft#page/7/mode/1up/search/vertex. Buy the book
Cite this article as:
McAdams, David E. Vertex. 12/17/2018. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/v/vertex.html.
Image Credits
Revision History
12/17/2018: Removed broken links, updated license, implemented new markup. (
McAdams, David E.)
8/7/2018: Changed vocabulary links to WORDLINK format. (
McAdams, David E.)
1/7/2010: Added "References". (
McAdams, David E.)
10/11/2008: Added vertex of a polynomial. (
McAdams, David E.)
6/7/2008: Corrected spelling. (
McAdams, David E.)
4/23/2008: Initial version. (
McAdams, David E.)