The angular distance of a point on the Earth's surface measured in degrees from the centre of the Earth east or west of the Greenwich Meridian is known as

The angular distance of a point on the Earth's surface measured in degrees from the centre of the Earth east or west of the Greenwich Meridian is known as longitude.

Let's break this down to make it simple:

Longitude lines are imaginary lines that run from the North Pole to the South Pole. The most important line is the Greenwich Meridian, also called the Prime Meridian, which is the reference point for measuring longitude. It is designated as zero degrees (0°) longitude. When you measure how far east or west a point is from the Prime Meridian, you are measuring the longitude.

This is different from latitude, which measures the distance north or south of the Equator. Longitude lines meet at the poles, whereas latitude lines are parallel to each other.

Overall, longitude helps us determine the precise location of a place on Earth by specifying how far east or west it is from the Prime Meridian.