What is Base (geometry)?
[[File:Cube.svg|thumb|A cube is made of six squares; the square is therefore the base of the cube.]] In [[Plane (mathematics)|plane]] [[geometry]], the '''base''' is the side on which a [[polygon]] rests on, and which is used as a referenced side for other measurements. The base of a [[triangle]] or [[quadrilateral]] is often written as <math>b</math>. It is used in the calculation of the [[area]] of a triangle and parallelogram.<ref>{{Cite web|last=|first=|date=2020-04-17|title=List of Geometry and Trigonometry Symbols|url=https://mathvault.ca/hub/higher-math/math-symbols/geometry-trigonometry-symbols/|archive-url=|archive-date=|access-date=2020-09-24|website=Math Vault|language=en-US}}</ref><ref>{{Cite web|title=Base - Math word definition - Math Open Reference|url=https://www.mathopenref.com/base.html|access-date=2020-09-24|website=www.mathopenref.com}}</ref><ref>{{Cite web|last=Russell|first=Deb|date=March 6, 2017|title=Definition of a Base in Mathematics|url=https://www.thoughtco.com/definition-of-a-base-2312351|archive-url=|archive-date=|access-date=2020-09-24|website=ThoughtCo|language=en}}</ref> Many [[geometry|geometric]] [[shape]]s of more than two [[dimension]]s are constructed by using regular two-dimensional shapes. For example, a [[tetrahedron]] is constructed with four triangles, and a [[cube]] with six [[square]]s. In that context, the shape that is used for construction is called base. The triangle is the base of the tetrahedron, and the square is the base of the cube. However, there are also geometric figures that are constructed using different shapes. A [[pyramid]], for example. uses one [[rectangle]] and four triangles. In that context, the rectangle is said to be the base of the shape. A [[cylinder]] uses a [[circle]] or an [[ellipse]] as a base. == Related pages == * [[Altitude]] == References == <references /> {{math-stub}} [[Category:Geometry]]