# Brianchon theorem

From Encyclopedia of Mathematics

In any hexagon (Fig.) circumscribed around a curve of the second order (a Brianchon hexagon) the straight lines connecting the opposite corners of the hexagon intersect at one point (Brianchon's point). This theorem is dual to the Pascal theorem, and was demonstrated by Ch.J. Brianchon in 1806.

Figure: b017640a

**How to Cite This Entry:**

Brianchon theorem. A.B. Ivanov (originator),

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Brianchon_theorem&oldid=19270

This text originally appeared in Encyclopedia of Mathematics - ISBN 1402006098