The Simson line is the line that contains the projections of the 3
feet from the heights of a triangle to the point P on the
circumference. The geometric locus described in this notebook is
that of the intersection point between the Simson line and a line
perpendicular to that line and what passes through the point
X20. The geometric locus is tritangent to the base
triangle and also to the deltoid that forms the trace of the Simson
line.