For example, consider real three-dimensional space, R 3 . The group of 3D rotations SO(3) acts naturally on this space as a group of 3 × × 3 matrices. This explicit realisation of the rotation group is known as the fundamental representation ρ ρ fund , so R 3 is a representation space. The full data of the representation is ( R 3 , SO(3) , ρ ρ fund ) . Since the dimension of this representation space is 3, this is known as the triplet representation for SO ( 3 ) , and it is common to denote this as 3 .