West longitude 105 is opposite to 75 east longitude. West longitude 105 degrees and east longitude 75 degrees form a meridian coil, which divides the earth into two hemispheres. The sum of the degrees of east longitude and west longitude is equal to 180 degrees, and the two meridians are corresponding, which can form a warp coil. A warp coil consisting of 20 degrees west longitude and 160 degrees east longitude divides the earth into two hemispheres.

Latitude and longitude are the combination of longitude and latitude, forming a coordinate system, which is called geographical coordinate system. It uses the spherical surface of three-dimensional space to define the space on the earth, and can mark the spherical coordinate system anywhere on the earth.

Development history

In 120, a young man also studied astronomy and geography in this ancient library. This is Claudius Ptolemy. Ptolemy integrated the previous research results, thought that maps should be drawn according to fixed points with known latitude and longitude, and put forward the concept of drawing latitude and longitude network on maps. To this end, Ptolemy measured the latitude and longitude of important cities and strongholds in the Mediterranean and compiled eight volumes of geographical works. Including the latitude and longitude of 8000 places.

In order to draw the longitude and latitude lines on the earth on a plane, he tried to draw them into simple sectors, thus drawing the famous Ptolemy map. /kloc-At the beginning of the 5th century, the navigator Henry began to put the Ptolemy map into practice. However, after repeated inspection, I found that this map is not practical. Some of Henry's captains said with regret that although we admired the famous Ptolemy very much, we found that the facts were contrary to what he said.