QL-P20: Orthocenter Homothetic Center

QL-P20 is the homothetic Center of the Reference Quadrilateral L1.L2.L3.L4 and the Quadrilateral formed by the lines parallel to the lines L1, L2, L3, L4 through the Orthocenters of the corresponding component triangles.
1st Coordinate
(m – n) (SB SC l2 - b2 SB l m - c2 SC l n + S2 m n)
1st DT-coordinate:
            (m2-n2) ((-a2 l2+b2 m2+c2 n2)2 - 4 Sa2 m2 n2)

        QL-P1.QL-P21                          (1 : 1 => QL-P20 = Midpoint of QL-P1, QL-P21)
        QL-P5.QL-P7   = QL-L1