Question

which circle forms the eastern and western hemisphere ????

Answer 1

The equator.. but it is a latitude.. you said a circle. I am not sure about it.

Answer 2

the prime meridine separates the earth into to the eastern and western hemisphere in the same way that the the equator separates the earth into the northern and Southern hemispheres.

The location of the Prime Meridian is 0 degrees longitude, just like the location of the equator is 0 degrees latitude.

The Prime Meridian also intersects eight nations. As a result, these nations are located in the Eastern as well as Western Hemispheres.