We live in the Northern Hemisphere. Study the map below. The imaginary line that separates East and West is the Prime Meridian. The Prime Meridian passes through Greenwich, England. These lines are measured in degrees.
Some lines have special names.
The Equator divides the world into the Northern and Southern hemisphere. The Prime Meridian is at zero degrees. The lines of Longitude meet at the North Pole and South Pole. These lines are used to find places. The profesor below is lost.