Carnot's theorem (named after
Lazare Carnot
Lazare Nicolas Marguerite, Count Carnot (; 13 May 1753 – 2 August 1823) was a French mathematician, physicist and politician. He was known as the "Organizer of Victory" in the French Revolutionary Wars and Napoleonic Wars.
Education and early ...
) describes a relation between
conic section
In mathematics, a conic section, quadratic curve or conic is a curve obtained as the intersection of the surface of a cone with a plane. The three types of conic section are the hyperbola, the parabola, and the ellipse; the circle is a specia ...
s and
triangle
A triangle is a polygon with three Edge (geometry), edges and three Vertex (geometry), vertices. It is one of the basic shapes in geometry. A triangle with vertices ''A'', ''B'', and ''C'' is denoted \triangle ABC.
In Euclidean geometry, an ...
s.
In a triangle
with points
on the side
,
on the side
and
on the side
those six points are located on a common conic section if and only if the following equation holds:
:
.
References
*Huub P.M. van Kempen
''On Some Theorems of Poncelet and Carnot'' Forum Geometricorum, Volume 6 (2006), pp. 229–234.
*Lorenz Halbeisen, Norbert Hungerbühler, Juan Läuchli: ''Mit harmonischen Verhältnissen zu Kegelschnitten: Perlen der klassischen Geometrie''. Springer 2016, {{ISBN, 9783662530344, pp. 40, 168–173 (German)
External links
''Carnot's Theorem for Conics''at cut-the-knot.org
Theorems about triangles