GERGONNE POINT OF A TRIANGLE.
© 2004-2009. RAIMOND A. STRUBLE, PhD.
DRAFT COPY ONLY.
9/27/2009.
© Raimond A. Struble.

Professor Emeritus
Department of Mathematics
North Carolina State University at Raleigh
Raleigh, NC.
This manuscript: http://www.infiniteproduct.info/struipgn.htm
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Problem: Recognizing that the Gergonne point of a triangle is the point of concurrence of rays which join the vertices with the points of contact for three mutually tangent circles centered at the vertices, determine the isosceles triangle whose Gergonne point falls onto the smallest circle.

FIGURE FOR SUBMITTER'S SOLUTION.

2757.


Proposer's solution: Amazingly, this configuration consists of the union of two 3×4×5 triangles, where the isosceles triangle becomes 5×5×8. The proof reduces to four applications of the cosine law, once the configuration is anticipated.

Last updated: 9/27/2009, by Raimond A. Struble, PhD.