Where is the starting point of measuring longitude?

Answer 1

The definition of zero longitude is the Prime Meridian . . . the line that joins

the north and south poles and crosses the official scratch in the floor of the

transit room of the Royal Observatory in Greenwich, UK.

Answer 2

-- Meridians of longitude join the north and south poles. The poles

are the two ends of every meridian.

-- Parallels of latitude are complete circles, and have no beginning or end.

Answer 3

The 'origin' of longitude is the Prime Meridian. It's an imaginary line between the

north and south poles that passes through the Royal Observatory in Greenwich UK.

The longitude of every point on that line is zero, and the longitude of every point

on Earth is an angle measured east or west of that line.

Answer 4

The "Prime Meridian" is defined as the line of zero longitude. It's the line that joins the north pole and south pole and passes through Greenwich, just outside of London. It's the boundary between east and west longitude.

Answer 5

In Greenwich, England 0 degrees longitude.

Answer 6

Each "meridian" of longitude joins the earth's north and south poles.

The "beginning" and "end" are not defined.

Answer 7

Every meridian of constant longitude has two ends ... at the north and south poles.

Every parallel of constant latitude is a circle, and has no beginning or end.

Answer 8

the Prime Meridian