Lines of Latitude and Longitude

Geographic grids are intersecting lines drawn on maps and globes. They are used to help locate and describe specific areas. Two sets of lines encircle the globe: lines of latitude and lines of longitude. The parallel lines of latitude are horizontal, running from east to west. The equator is the imaginary line from which latitude is measured; it is equidistant from the poles, dividing the globe into the northern and southern hemispheres. Unlike lines of latitude, which become progressively shorter as they near the poles, all of the lines of longitude are the same length. Longitudinal lines run from north to south, each individual vertical line intersecting both poles. The prime meridian is an arbitrarily selected line from which all of the others are measured. Any location on the globe can be described in terms its angular distance from the reference points of the equator (0° latitude) and the prime meridian (0° longitude).