ProtonMass is the mass of a proton.
RydbergConstant is an atomic constant appearing in the Rydberg formula expressing the wave-numbers of the lines in a spectral series.
SpeedOfSound is the speed of sound at sea level in the standard atmosphere.
VacuumPermeability is the permeability of vacuum, a universal constant.
VacuumPermittivity is the permittivity of vacuum, a universal constant.
Area
(Polytopes Package Symbol) Area[polygon] gives the area of polygon polygon, when the edges of polygon have unit length.
NumberOfEdges[polytope] gives the number of edges of polytope.
NumberOfFaces[polytope] gives the number of faces of polytope.
NumberOfVertices[polytope] gives the number of vertices of polytope.