An equilateral triangle
Source: Iberoamerican Olympiad 1992, Problem 3
May 14, 2007
geometrycircumcircletrigonometryinradiusinequalitiesincentergeometry proposed
Problem Statement
Let be an equilateral triangle of sidelength 2 and let be its incircle.
a) Show that for every point on the sum of the squares of its distances to , , is 5.
b) Show that for every point on it is possible to construct a triangle of sidelengths , , . Also, the area of such triangle is .