Definition:Polygon/Vertex

Definition

 * IrregularPolygon.png

A corner of a polygon is known as a vertex.

Thus, in the polygon above, the vertices are $A, B, C, D$ and $E$.

Linguistic Note
The plural of vertex is vertices.

The word vertex is Latin for peak, from which the irregular plural form

Also defined as
, in, uses the term vertex to mean the corner of a polygon furthest up the page from the base.



Also see

 * Definition:Height of Polygon


 * Definition:Apex of Triangle

Note
The vertices and the sizes of the internal angles of those vertices are frequently referred to by the same letter.

Thus the angle of vertex $A$ is called angle $A$ and denoted $\angle A$.

This is considered by some to be an abuse of notation but its convenience outweighs its disadvantages.