Question

2. Meridian marked as 0°​

Answer 1

Answer:

because it is counted as the starting point, so every initial point is marked from 0

Answer 2

prime meridian

The meridian that runs through Greenwich, England, is internationally accepted as the line of 0 degrees longitude, or prime meridian. The antimeridian is halfway around the world, at 180 degrees. It is the basis for the International Date Line.