Original: In geometry , a simplex ( plural simplexes or simplices ) is a generalization of the notion of a triangle or tetrahedron to arbitrary dimension . Specifically , an n-simplex is an n-dimensional polytope which is the convex hull of its n + 1 vertices .
Simplified: In geometry , a simplex ( plural : simplices or simplexes ) , sometimes called n-simplex is the n-dimensional analog figure of the triangle .