Square kilometre
A unit of area equal to one million square metres, the area of a square with sides one kilometre long.
Square metre: The SI unit of area, equal to the area of a square with sides one metre long. A square kilometre is exactly one million square metres.
Topographic map: A map that represents terrain and natural or human-made features, often with contour lines. Map scales let mapped regions be measured and reported in square kilometres.
Hectare: A metric unit of area equal to 10,000 square metres. A square kilometre contains exactly 100 hectares, a more convenient unit for many land parcels.
Central Park: A large public park in Manhattan, New York City, covering about 3.4 square kilometres. Its area shows that a square kilometre is smaller than a major urban park.
Kilometre: A metric unit of length equal to 1,000 metres. Squaring a kilometre gives the side length used to define this area unit.
Geographic information system: A system for capturing, managing, analyzing, and displaying geographically referenced data. GIS calculations commonly report land-cover and administrative areas in square kilometres.
Square mile: A unit of area equal to the area of a square one mile on each side. It is a common non-metric alternative for describing large regions.
Monaco: A sovereign city-state on the French Riviera with an area of about two square kilometres. Its national territory spans only a few square kilometres.
Area: A measure of the two-dimensional extent of a surface or shape. The square kilometre measures area rather than distance.
Land surveying: The measurement and mapping of land boundaries, positions, and features. Surveyed parcels and territories can be aggregated into square-kilometre areas.