The equator is located at 0 degrees latitude. Because the Earth is widest at the equator, it is the longest line of latitude at 24,901.55 miles. Lines of latitude are imaginary lines that measure degrees north and south of the equator.
The equator divides the Earth into northern and southern hemispheres. Other important lines of latitude are the Tropic of Cancer and the Tropic of Capricorn, at 23.5 degrees north and south latitude respectively. The area in between these two lines of latitude is known as the tropics. The North Pole is located at 90 degrees north latitude, and the South Pole is situated at 90 degrees south latitude.