Answer:
The line that separates the Eastern and Western Hemispheres is the Prime Meridian.
Explanation:
Earth, because of the needs of humans, is artificially divided into hemispheres. On one side it is the division of Northern Hemisphere and Southern Hemisphere, and on the other side is the division of Eastern Hemisphere and Western Hemisphere. The line that separates and defines the latter is the Prime Meridian.
The Prime Meridian has been set at Greenwich. It has a longitude of zero, thus it is the starting point for measuring longitude, both east and west. Everything located east of the Prime Meridian and to the Date Line is part of the Eastern Hemisphere. Everything that is located west of the Prime Meridian and to the Date Line is part of the Western Hemisphere.
