Editing Length (section)

{{Short description|Measure of distance in physical space}}
{{About|a physical measurement}}
{{Redirect|Width||Width (disambiguation)}}
{{Redirect|Breadth|ship measurements|Breadth (nautical)}}
{{Use British English|date=March 2018}}
{{Infobox physical quantity
| name       = Length
| image      = Scale kilometres miles.svg
| caption    = The [[Metric system|metric]] length of one [[kilometre]] is equivalent to the [[imperial measurement]] of 0.62137&nbsp;[[mile]]s.
| unit       = [[metre]] (m)
| otherunits = see [[unit of length]]
| symbols    = {{mvar|l}}
| dimension  = <math>\mathsf{L}</math>
| extensive  = yes
}}

'''Length''' is a measure of [[distance]]. In the [[International System of Quantities]], length is a [[quantity]] with [[Dimension (physical quantity)|dimension]] distance. In most [[systems of measurement]] a [[Base unit (measurement)|base unit]] for length is chosen, from which all other units are derived. In the [[International System of Units]] (SI) system, the base unit for length is the [[metre]].<ref name=":0" />
 
Length is commonly understood to mean the most extended [[size|dimension]] of a fixed object.<ref name=":0">{{Cite encyclopedia|url=http://wordnetweb.princeton.edu/perl/webwn?s=length|encyclopedia=WordNet|title=Length|access-date=15 March 2020|archive-url=https://web.archive.org/web/20160925172753/http://wordnetweb.princeton.edu/perl/webwn?s=LENGTH|archive-date=25 September 2016|url-status=live}}</ref> However, this is not always the case and may depend on the position the object is in.

Various terms for the length of a fixed object are used, and these include [[height]], which is vertical length or vertical extent, width, breadth, and depth. ''Height'' is used when there is a base from which vertical measurements can be taken. ''Width'' and ''breadth'' usually refer to a shorter dimension than ''length''. ''Depth'' is used for the measure of a [[third dimension]].<ref>{{Cite web|url=http://thinkmath.edc.org/resource/measurement-length-width-height-depth|title=Measurement: Length, width, height, depth|website=Think Math!|access-date=15 March 2020|archive-url=https://web.archive.org/web/20200224001255/http://thinkmath.edc.org/resource/measurement-length-width-height-depth|archive-date=24 February 2020|url-status=live}}</ref>

Length is the measure of one spatial dimension, whereas [[area]] is a measure of two dimensions (length squared) and [[volume]] is a measure of three dimensions (length cubed).