Are (a)

The are (symbol: a) is a metric unit of area equal to 100 square metres, or the area of a square with 10-metre sides. First introduced in France in 1795 as part of the original metric system, it served as the base unit for land measurement before being largely superseded by its decimal multiple, the hectare. Although not an official SI unit, the are remains recognized for land registration and agricultural surveying in several European countries.