- noun the measurement of angles, commonly by dividing a complete circle into 360 degrees, with each degree divided into 60 minutes and each minute into 60 seconds
- The angles between objects on the celestial sphere are the basis of all astronomical information, defining where to find objects and how they move in the sky and relate to each other. There are two main systems of angular measure. One uses degrees (360 to a circle), minutes (60 to a degree) and seconds (60 per minute) while the other uses radians, the angle formed by a length equal to the radius of a circle seen at its circumference. About 6.3 radians make a full circle. The Sun or the full Moon are about half a degree across in the sky.
- The deviation between two lines that meet at a point, measured in degrees, minutes and seconds.