How is longitude defined?

Longitude is defined as the distance east or west of the prime meridian, which is an imaginary line that runs from the North Pole to the South Pole and is designated as 0 degrees longitude. This definition is essential for geographical navigation and mapping, as longitude allows us to determine a location's position relative to this central reference line. Together with latitude, which measures distance north or south of the equator, longitude helps in pinpointing exact locations on the Earth's surface.

The prime meridian serves as the starting point for measuring longitude, with degrees increasing to 180 degrees east and west. This system is crucial for various applications, such as global positioning systems (GPS) and timekeeping, as the Earth rotates 360 degrees, leading to the division of the world into different time zones.

In contrast, the other options define different concepts unrelated to longitude. The nature of latitude, which is concerned with measuring positions north or south of the equator, the measurement of land area, and the angle of elevation from sea level do not pertain to the definition of longitude. Adjusting our understanding of geographical coordinates is fundamental for students studying social studies, geography, and related fields.