Coxeter groups

abstract group that admits a formal description in terms of reflections (or kaleidoscopic mirrors)

pictoral representation of symmetry

Group realized geometrically by reflections across the sides of a triangle

concept in geometry

discrete group which is generated by a set of reflections of some space

a mathematical structure that describes the symmetries of the number line and the regular triangular tesselation of the plane, as well as related higher dimensional objects