The latitude is an arbitrary line used in the geographical coordinate system along with longitude to locate a point on the Earth. The latitude is the line or trajectory of a point on the surface of the Earth as it rotates from west to east. If the point is at the surface of the Earth at its center, the latitude passing through it is known as the equator. It is said to be at 0° to the arbitrary line that connects the center of the Earth to the point on the surface. This angle increases up to 90° towards either of the poles of the Earth at regular intervals. Each line drawn at those intervals are called as the parallels. The well-known parallels are the 23.4° N parallel called the Tropic of Cancer and the 23.4° S parallel called the Tropic of Capricorn.
Frequently Asked Questions
How to find the latitude of my position without a map or GPS?
The latitude of your position on Earth can be found by using a quadrant to point at the pole star Polaris if you are at the north pole. As Polaris is bright enough to be seen with the naked eye and is located straight above the north pole, it is easy to measure your latitude if you know the angle between Polaris and your horizon. When you are exactly at the north pole, Polaris will be right above your head, and the angle will be 90°. And hence, the latitude will be 90° too. When you are at the equator, you will find Polaris at the horizon, at a 0° angle, which is the equator. This angle is also known as the altitude of the star. The resulting measurement obtained from your position in the northern hemisphere will be the angle of your latitude. To measure your longitude, read this answer.
How to find the latitude in the southern hemisphere?
If you are in the southern hemisphere, Polaris cannot be seen. The southern pole star is Sigma Octantis, which is fainter and a little closer to the southern pole. Measuring the altitude of Sigma Octantis will be the latitude of your position if you are in the southern hemisphere.