A vertex is a corner. More than one vertex are called vertices. A vertex is a point where two or more lines, curves, rays, or sides meet, and is often represented by letters such as
For example, the vertex of an angle is the point where the two edges of the angle intersect, and a vertex of a cube is simply one of its corners—of which there are 8.
The concept of vertex applies to both two-dimensional and three-dimensional geometrical objects. For example, a tetrahedron has 4 vertices, and a pentagon has 5 vertices.