An example of Cartesian coordinates system.
Original author was <a href="https://en.wikipedia.org/wiki/User:Gustavb" class="extiw" title="en:User:Gustavb">en:User:Gustavb</a>
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Derivative of <a href="//commons.wikimedia.org/wiki/File:Cartesian_coordinates_2D.svg" title="File:Cartesian coordinates 2D.svg">Image:Cartesian coordinates 2D.svg</a>. Captions removed by <a href="https://af.wikipedia.org/wiki/User:Laurens" class="extiw" title="af:User:Laurens">Laurens</a> (for use in non-English articles) and originally uploaded to the <a class="external text" href="https://af.wikipedia.org">Afrikaans Wikipedia</a>.