Vertices

In an equilateral triangle with vertices A, B and C, the distance from A to B is the same distance as from B to C, or from C to A.

In geometry, a triangle's Fermat point is a point defined such that its total distance from the three triangle vertices is the minimum possible.

How many vertices and faces does a pentagonal prism have?

Any simple graph can be treated as a subset of the set of all two-element subsets of the set of its vertices.

How many vertices does a cube have?

In general, the area of a quadrilateral cannot be written as a function of its side lengths, but there are exceptions, such as rectangles or more generally cyclic quadrilaterals, whose vertices lie on a common circle.