# Tetrahedral coordinates

From Encyclopedia of Mathematics

*of a point $P$ in three-dimensional space*

Numbers $x_1,x_2,x_3,x_4$ which are proportional (with given coefficient of proportionality) to the distances from $P$ to the faces of a fixed tetrahedron, not necessarily regular. Analogously, one may introduce general normal coordinates for any dimension. The two-dimensional analogues of tetrahedral coordinates are called trilinear coordinates.

See also Barycentric coordinates.

#### References

[a1] | H.S.M. Coxeter, "Regular polytopes" , Dover, reprint (1973) pp. 183 |

**How to Cite This Entry:**

Tetrahedral coordinates.

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Tetrahedral_coordinates&oldid=53612

This article was adapted from an original article by D.D. Sokolov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article