**Vertex in an angle:** The point in which the sides of the angle meet. That is, the common endopoint of the two rays.

**Vertex angle:** The point about which an angle is measured is called the angle´s vertex, and the angle

associated with a given vertex is called the vertex angle.

**Vertex in a polygon**: The vertices of a polygon are the points where its sides intersect.

**Vertex of a cone or a pyramid: **The vertex of a cone or a pyramid is the point opposite to the base. That is, the point placed (vertically) above the base.

**Vertices of a polyhedron: **A vertex od a polyhedron is a point at which three or more edges intersect.

**Diagonals in a polygon: **The diagonal of a polygon is a line segment that joins two non-consecutive vertices.

The number of diferent diagonals is given by the formula:

where n is the number of sides or vertices.