GENERAL KNOWLEDGE

Detailed explanation-1: -For example, the plane of the 90th line of longitude, on which New Orleans is located, forms a 90° angle with the plane of the prime meridian. All places on the 90th line of longitude west of the prime meridian, therefore, are at 90° west longitude. The prime meridian is designated zero degrees (0°) longitude.

Detailed explanation-2: -North America. Also, New Orleans is located where the parallel of latitude that is 30 degrees north of the Equator crosses the meridian of longitude that is 90 degrees west of the Prime Meridian.

Detailed explanation-3: -Any line of longitude (a meridian) can serve as the 0° longitude line. However, there is an international agreement that the meridian that runs through Greenwich, England, is considered the official prime meridian.