What scale is used for measuring longitude?

Longitude is measured using degrees, which are units that make up a coordinate system used in navigation and mapping. The longitude scale specifically refers to the system based on the prime meridian and extends to 180 degrees east and west. Each degree of longitude corresponds to a specific measure of distance on the Earth's surface, but the primary purpose of the longitude scale is to establish a geographical reference.

This concept is integral for navigators, as it aids in determining a vessel's east-west position relative to the prime meridian. The degrees of longitude are also further divided into minutes and seconds for more precise navigation. Understanding this scale allows mariners to plot their course accurately and maintain their bearings, making it an essential element in maritime navigation. Other options do not pertain to measurement of geographic position and therefore do not accurately describe the appropriate scale used for measuring longitude.