n≥=3 lines lie in the same plane and are concurrent at point O.
If y = mx is the equation of a line passing through the origin O
(where m is the slope), then mk labels the line y = tan(k*180°/n)*x
(for k = 0 to n-1). Note: If n is even and
k = n/2, then line mk is perpendicular to line m0.
Point P (distinct from O) is an arbitrary point
in the plane of the n lines. Fi is the foot of the perpendicular from
point P to line mi (for i = 0 to n-1).