Editing Analytic geometry (section)

===Cartesian coordinates (in a plane or space)===
{{main|Cartesian coordinate system}}
The most common coordinate system to use is the [[Cartesian coordinate system]], where each point has an ''x''-coordinate representing its horizontal position, and a ''y''-coordinate representing its vertical position.  These are typically written as an [[ordered pair]] (''x'',&nbsp;''y'').  This system can also be used for three-dimensional geometry, where every point in [[Euclidean space]] is represented by an [[Tuple|ordered triple]] of coordinates (''x'',&nbsp;''y'',&nbsp;''z'').