Meridian (geography)

This article is about the geographical concept. For other uses of the word, see Meridian. A meridian (or line of longitude) is an imaginary arc on the Earth's surface from the North Pole to the South Pole that connects all locations with a given longitude. The position of a point on the meridan is given by the latitude. Each meridian is perpendicular to all circles of latitude at the intersection points. Each is also the same size, being half of a great circle on the Earth's surface and therefore measuring 20,003.93 km.
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