In
geometry, the Mandart inellipse of a
triangle is an
ellipse that is
inscribed within the triangle,
tangent to its sides at the contact points of its
excircles (which are also the vertices of the
extouch triangle and the endpoints of the
splitters).[1] The Mandart inellipse is named after H. Mandart, who studied it in two papers published in the late 19th century.[2][3]
where a, b, and c are sides of the given triangle.
Related points
The center of the Mandart inellipse is the
mittenpunkt of the triangle. The three lines connecting the triangle vertices to the opposite points of tangency all meet in a single point, the
Nagel point of the triangle.[2]
See also
Steiner inellipse, a different ellipse tangent to a triangle at the midpoints of its sides