# What are the Longitude Lines?

The longitude lines are a set of circles on a globe that show how far east or west of the prime meridian a location is. The prime meridian is the line that runs through the Earth’s center and is used as the starting point for measuring distances around the world.

The longitude lines are drawn at a uniform interval of degrees and are divided into 180 degrees. Each line is numbered from 0 to 179 in increments of 5 degrees. Locations that are east of the 0 degree line are said to be east of the prime meridian, and locations that are west of the 0 degree line are said to be west of the prime meridian.

Latitude lines are also drawn on a globe, but they are not divided into 180 degrees. Locations that are north of the equator are said to be north of the prime meridian, and locations that are south of the equator are said to be south of the prime meridian.

The longitude lines and latitude lines intersect at right angles at every point on the globe. The intersections of the longitude lines and latitude lines form the vertices of the world’s major landmasses.