Defining bearings and azimuths with examples.

Angles can be described as azimuths or bearings. There are 360 degrees in a circle with 60 minutes in a degree and 60 seconds in a minute. The azimuth of a line is the direction measured clockwise from a standard direction (North is the common standard direction). Azimuths must have a positive value and be less than 360°. The bearing of a line is the direction within a quadrant with reference to a meridian (North or South) line. The reference is selected based on the closest meridian; therefore, bearing angles must be less than 90°. While the azimuth is described by a single numerical value, bearings must reference the leading latitude direction (North or South), the angle turned from the meridian, and the direction of the turn from the meridian (East or West). For example, the SW line (the line that bisects the SW quadrant), has an azimuth of 225° and a bearing of S45°W. The azimuth of 225° is the angular measurement from North and the bearing first lists the reference axis, South, then the angle of turn towards the horizon, West.


Line AB: The given angle NAB is the angle measured from North of 24°07'53". Therefore, the azimuth of line AB is directly known of 24°07'53". The bearing of line AB is also directly known of N24°07'53"E.

Line AC: The given angle SAC is the angle measured from South of 58°18'49". Therefore, the azimuth can be calculated by subtracting this angle from 180°, the resulting azimuth of line AC is 121°41'11". The bearing of line AC is referenced from South towards the East as S58°18'49"E.

Line AD: The given angle WAD is the angle measured from West of 47°39'14". Therefore, the azimuth can be calculated by subtracting this angle from 270°, the resulting azimuth of line AD is 222°20'46". The bearing of line AD is referenced from South towards the West, so the given angle must be subtracted from 90°, which results in a bearing of S42°20'46"W.