Area is a measurement of the size of a surface.A surface is ( in mathematics and topology ) a two-dimensional manifold.The area term can be used in a non-mathematical context to be mean "vicinity".
The SI unit of area is the square metre. The two main systems to measure area are the metric and the English system.
Commonly used units are the are , hectare and the square kilometre , that are derived from the square metre.
In the Imperial system of units, commonly used units of length are the square foot , the square yard, the acre , and the square mile.
Acre (ac or A) is a unit of area used for measuring real estate in English-speaking countries.It is equal to 4840 square yards. There are 640 acres in a square mile. The "Acre," is an old english word meaning a field and was originally defined as the area that could be plowed in a day by a yoke of oxen.
Hectare (ha) is a metric unit of land area, equal to 100 ares . One hectare is a square hectometer, that is, the area of a square 100 meters on each side: exactly 10 000 square meters or approximately 11 959.9 square yards,107 639.1 square feet or 2.471 054 acre.
The term are can also be used in a non-mathematical context to be mean ' land ' or 'geographical area';
This is a list of teritories of the world sorted by total area(total areas are included, covering land and inland water bodies ( reservoirs, rivers,lakes). Marine internal waters, territorial waters and Exclusive Economic Zones are not included):
- Vatican City - - 440 000 m²
- Los Angeles, California, USA - 1290 km²
- California,USA - 423,970 km²
- Russia - 17,098,242 km²
- Republic of China - 9,640,821 km²