An IMO Triangle Problem

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The International Mathematical Olympiad (IMO) of 2006 was held in Slovenia. This Demonstration shows that moves along the brown circle with center at the intersection of the circumcircle and the bisector of the angle
. The point
is constrained to move so that
. This is based on a problem presented at IMO as follows. Let ABC be a triangle with incentre
. A point
in the interior of the triangle satisfies
. Show that
, and that equality holds if and only if
.
Contributed by: Oleksandr Pavlyk (January 2008)
Open content licensed under CC BY-NC-SA
Snapshots
Details
This was the first of 6 problemspresented at IMO.
Snapshot 1: Right triangle
Snapshot 2: Isosceles triangle
Snapshot 3: Equilateral triangle
Permanent Citation
"An IMO Triangle Problem"
http://demonstrations.wolfram.com/AnIMOTriangleProblem/
Wolfram Demonstrations Project
Published: January 17 2008