Answer:
0° longitude
Step-by-step explanation:
The prime meridian is located at Greenwich in England, and it represents the line of 0° longitude. This imaginary line separates the earth into two equal halves, commonly considered as the eastern and the western hemisphere.
This line is perpendicular to the line of the equator. It helps in determining the time zone and also for the use of navigation purposes, whether a person is moving towards east or west.