Which tool is commonly used to measure an azimuth?

The compass is commonly used to measure an azimuth because it directly indicates the cardinal directions and allows for the determination of an angle relative to true north or magnetic north. The azimuth is expressed in degrees from the North direction, ranging from 0° to 360°, and a compass provides a straightforward means to establish these bearings accurately.

In contrast, a protractor is designed primarily for measuring angles in two-dimensional geometric contexts rather than for the purpose of navigating or determining orientations in the field. Rulers and measuring tapes are tools intended for linear measurement, such as distances or lengths, which do not pertain to angular measurements or directional bearings. The distinction lies in the function of each tool; the compass is specifically tailored to directional orientation, making it essential for azimuth measurements.