Any functions that operate on angles use radians as the unit of angle.

To supplement these five, two units of angle measurement that are also independent are recognized.

Any unit of angle can be used for declination, but it is often expressed in minute of arc.

In astronomy, the minute is a unit of angle, the minute of right ascension.

In surveying, the gradian is the default unit of angles in many parts of the world.

This is got from the definition: a parsec is the distance from the Sun to an object which has a parallax angle of one arcsecond (an arcsecond being a unit of angle equaling 1/60th of an arcminute or 1/3600th of a degree).

Since SI has adopted the radian as its preferred but dimensionless unit of angle, but left its explicit writing discretionary in unit combinations, the radian per second has perhaps a better claim than the cycle per second to being equivalent to the reciprocal second.