2.Triangles intercepted by forward parallelians
Given a triangle ABC,we mean by a parallelian a directed ray parallel to one
of the sides, forward if it is along the direction of AB, BC,or CA,and backward
if it is along BA, CB,or AC.In this paper we study the question: how should
one choose the point P so that so that the triangle XYZ intercepted by forward
parallelians through P is equilateral? See Figure2.
We solve this problem by
performing an analysis using homogeneous barycentric coordinates.If P =(u :
v : w),then X, Y ,and Z have coordinates