This article is about a foot as a unit of length. For other uses of foot, see foot (disambiguation).
A foot (plural: feet) is a non-SI unit of distance or length. The popular belief is that original standard was the length of a man's foot. The average foot length is about 240 mm (9.4 in) for current Europeans. About 996 of 1000 British men have a foot that is less than 12 inches long. A plausible explanation for the missing inches is that the measure did not refer to a naked foot, but to the length of footwear. This is consistent with the measure being convenient for practical purposes such as on building sites etc. People almost always pace out lengths whilst wearing shoes or boots, rather than removing them and pacing barefoot.
There are twelve inches in one foot and three feet in one yard.
The standardization of weights and measures has left several different standardized foot measures. The most commonly used foot today is the imperial foot, which is defined to be exactly 0.3048 metres. This unit is sometimes denoted with a prime (e.g. 30′ means 30 feet), often approximated by an apostrophe. Similarly, inches can be denoted by a double prime (often approximated by a quotation mark), so 6′2″ means 6 feet 2 inches.
The foot as a measure was used in almost all cultures. The first known standard foot measure was from Sumeria, where a definition is given in a statue of Gudea of Lagash from around 2575 BC. The imperial foot was adapted from an Egyptian measure by the Greeks, with a subsequent larger foot being adopted by the Romans.
In addition to the current standard imperial foot, there is also a slightly different U.S. survey foot, used only in connection with surveys by the U.S. Coast and Geodetic Survey, defined as exactly 1200/3937 m.[1] (http://www.ngs.noaa.gov/PUBS_LIB/FedRegister/FRdoc59-5442.pdf)
A foot (plural: feet; symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperialunits, and United States customary units.
In 1958 the United States and countries of the Commonwealth of Nations defined the length of the international yard to be 0.9144 metres.
There are 6076 feet in a nautical mile, which is approximately one minute of arc on the Earth's surface.
Unit, as defined by the dictionary, is "a determined quantity adopted as a standard of measurement.
When one use a unit to measure with the sole purpose of measuring, any unit may be adopted as a standard, as long as one is familiar with the standard and has a way to reference to the standard.
Therefore, any unit system using feet should be replaced with systems such as the metric system, which as least provides some convenience for having a consistent scaling factor, because using a unit system that employs feet as a unit to take measurements is simply as ridiculous as the performance.
Feeds |
Contact