Simplex - Wikipedia
In geometry, a simplex (plural: simplexes or simplices) is a generalization of the notion of a triangle or tetrahedron to arbitrary dimensions.. For example, a 0-simplex is a point,; a 1-simplex is a line segment,; a 2-simplex is a triangle,; a 3-simplex is a tetrahedron,; a 4-simplex is a 5-cell.; Specifically, a k-simplex is a k-dimensional polytope which is the convex hull of its k + 1 ...