A Meridian Arc is a segment of a circle that represents a specific angle of the Earth's surface, measured from the North to the South Pole. It is used in geography and navigation to help determine locations and distances on the globe. The arc is part of a larger system of meridians, which are imaginary lines that run from pole to pole. Meridian arcs are essential in cartography, as they assist in creating accurate maps and understanding the Earth's coordinate system. They are also important in astronomy, where they help in tracking celestial objects and understanding their positions relative to the Earth.