Romanian District Olympiad 2015, Grade VII, Problem 4
Source:
September 25, 2018
geometrycenter of gravity
Problem Statement
At the exterior of the square it is constructed the isosceles triangle with is the intersection of the bisector line of the angle with its perpendicular that passes through is the intersection of the with its perpendicular that passe through is the intersection of with
If is the center of gravity of the triangle prove that and are parallel.