Regional Olympiad - FBH 2009 Grade 12 Problem 2
Source: Regional Olympiad - Federation of Bosnia and Herzegovina 2009
September 28, 2018
geometryEquilateral Trianglefixed
Problem Statement
Let be an equilateral triangle such that length of its altitude is . Circle with center on the same side of line as point and radius touches side . Circle rolls on the side . While the circle is rolling, it constantly intersects sides and . Prove that length of an arc of the circle, which lies inside the triangle, is constant