The Cartesian Co-Ordinate System

3D software packages use the Cartesian coordinate system to create the illusion of working in three-dimensional space.
This system is the same coordinate system used for teaching algebra.

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It was a French mathematician called Rene Descartes who first developed the Cartesian coordinate system, this was in 1637.
He created this system in an effort to merge algebra and Euclidean geometry.
His work has played an important role in the development of analytic geometry, calculus and cartography.

The 2-dimensional Cartesian system is commonly defined using two axes, both perpendicular to each other as you can see in the picture below.
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The horizontal axis is labelled X.
The vertical axis is labelled Y.
These axes form the X-Y plane.

The point where the X and Y axes meet is known as the origin.
This is labelled O.
This origin represents the centre of the coordinate universe.

The Z axis was added in the 19th century.
The Z axis is called the depth axis and it runs at right angles to the xy plane and also extends forever in both directions. This third axis enables us to locate any point in three-dimensional space.

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