Naming the Lines: Longitude

(Page 6 of 9 pages)
view from aboveHere is a drawing of the earth from above, showing the meridians of longitude. Do you remember that they run from pole to pole? One of these (the prime meridian) is named 0° longitude.

To the west they are all numbered from 1° West longitude to 180° longitude. To the East of 0°, they are named from 1° east longitude to 180°.