Answer:
The prime meridian is a longitude line of 0 degrees.
Step-by-step explanation:
The prime meridian has been set up in Greenwich, UK. It is an imaginary line that represents O degrees of longitude. This line, like all other meridians, runs from the North Pole to the South Pole and has the same length as all of the other meridians.
From the prime meridian, there are 180 degrees west and 180 degrees east. This is the line that divides the world in the Western and Eastern Hemispheres. The prime meridian is also the line from which time is counted either plus or minus, as it is at 0+ time zone, and everything east of it is plus, while everything west is minus. On the opposite side of the world of the prime meridian, we have the line that represents the start of time.