All places on Earth west from Prime Meridian to 180 degree are in the western hemisphere.
The anti-meridian opposite the prime meridian
180 degree meridian is the meridiam ospposite to the Prime Meridean or The Greenwich Meridian. It helps to find the location of a place. The 180 degree west and the 180 degree east are the same meridians. Whereas, the International Date Line or the IDL is an imaginary line that runs ALONG the 180 degree meridian. It bend slightly to avoid land. If a person travells eastward of it , he /she gains a day, but if a person travells westward of it he/she loses a day.
prime meridian International Date Line
eastern hemisphers
In the Western Hemisphere.
The eastern and western ones are.
I d l
90 degrees west
Longitude is labeled from zero (at the Prime Meridian) to 180 degreesin each direction, east and west, from it.
North and South are divided by the Equator. East and West are divided by the 0 degree meridian and the 180 degree meridian.
90 degrees west