Status of angular units

Angles should be considered as relative, i.e., dimensionless derived quantities. It is only by accepting the condition that angles are dimensionless that it is possible to maintain the generally accepted system of equations relating angles to other quantities, the accepted form of transcendental-function expansions in powers of angles, etc., as well as the normal system of dimensions. The angle units are relative, i.e., they belong to the category of derived units and, therefore, the coherent angle units, the radian and steradian, must be included in the category of derived SI units. The question of referring the angle units to the category of derived SI units should be proposed for discussion by the Consulting Committee on Units and an appropriate draft resolution should be presented to the forthcoming General Conference on Weight and Measures.