info prev up next book cdrom email home

Nobbs Points

\begin{figure}\begin{center}\BoxedEPSF{NobbsPoints.epsf scaled 800}\end{center}\end{figure}

Given a Triangle $\Delta ABC$, construct the Contact Triangle $\Delta DEF$. Then the Nobbs points are the three points $D'$, $E'$, and $F'$ from which $\Delta ABC$ and $\Delta DEF$ are Perspective, as illustrated above. The Nobbs points are Collinear and fall along the Gergonne Line.

See also Collinear, Contact Triangle, Evans Point, Fletcher Point, Gergonne Line, Perspective Triangles


Oldknow, A. ``The Euler-Gergonne-Soddy Triangle of a Triangle.'' Amer. Math. Monthly 103, 319-329, 1996.

© 1996-9 Eric W. Weisstein