What is Metre?
[[File:5 metres (8349446738) (2).jpg|thumb|right|This giraffe is nearly five metres tall.]] A '''metre''' (US spelling, ''meter'') is the basic [[units of measurement|unit]] of [[length]] in the [[SI]] measurement system. The [[symbol]] for the metre is '''m'''. The first meaning (in the [[French Revolution]]) was one ten-millionth of the [[distance]] between the [[Earth]]'s [[equator]] and the [[North Pole]] along the [[Paris]] [[meridian]].<ref name=NIST>{{cite web|url=http://physics.nist.gov/cuu/Units/meter.html|title=Historical context of the SI|publisher=US Government - National Institute of Standards and Technology}}</ref> The metre is now defined as the [[distance]] [[light]] travels in a [[vacuum]] in 1/299,792,458 of a [[second]].<ref name=NIST/> In the [[Imperial unit|imperial]] system of measurement, one yard is 0.9144 metres (after international agreement in 1959), so a metre is very near to 39.37 [[inch]]es: about 3.281 [[Foot (unit of length)|feet]], or 1.0936 [[US yard|yards]]. [[File:Platinum-Iridium meter bar.jpg|thumb|right|The bar (made of [[platinum]] and [[iridium]]) that defined the length of a metre until 1960.]] ==Units multiples== * 0.000 000 000 000 000 000 000 001 Ym (yotametre) = 1 m * 0.000 000 000 000 000 000 001 Zm (zetametre) = 1 m * 0.000 000 000 000 000 001 Em (exametre) = 1 m * 0.000 000 000 000 001 Pm (petametre) = 1 m * 0.000 000 000 001 Tm (terametre) = 1 m * 0.000 000 001 Gm (gigametre) = 1 m * 0.000 001 Mm (megametre) = 1 m * 0.001 km ([[kilometre]]) = 1 m * 0.01 hm (hectometre) = 1 m * 0.1 dam(decametre) = 1 m * 1 m (metre) * 10 dm (decimetres) = 1 m * 100 cm ([[Centimetre|centimetres]]) = 1 m * 1000 mm ([[Millimetre|millimetres]]) = 1 m *