Definition: is a unit of land area used in the imperial and US customary systems.
square acre (~4047 square meters)
Current use: Acres are used in countries including the USA, the UK, Ghana, India, Canada, and others.
History: In the Middle Ages, the acre was defined as the area that a yoke (pair) of oxen could typically plow within one day, using a wooden plow. Before the metric system was adopted, many countries used their own versions of the acre. The most commonly used acre today, the international acre, which was defined in 1959.
