What type of units are the radian and steradian classified as within the SI system?

The radian and steradian are classified as supplemental units within the International System of Units (SI). Supplemental units are defined to represent specific measurements related to angles and solid angles, respectively. The radian is used to measure angles, while the steradian measures solid angles. Both of these units play a significant role in various fields of science and engineering, particularly in calculations involving rotational movements and three-dimensional geometry.

Base units, such as the meter, kilogram, second, and kelvin, provide fundamental measurements from which other units are derived. Derived units, on the other hand, are combinations of base units that describe more complex measurements, such as velocity (meters per second) or pressure (pascals). Imperial units refer to a measurement system that is separate from the SI system, primarily used in the United States and a few other countries.

Thus, the identification of the radian and steradian as supplemental units clarifies their unique role within the SI framework and highlights their importance in representing angular measurements.