A triangle has the lines ar +2hry + by = 0 for two of its sides and the point (p; q) for its ortho-centre. prove that the equation of the third side is (a+b)(pr

A triangle has the lines ax +2hxy + by = 0 for two of its sides and the point (p; q) for its ortho-centre. Prove that the equation of the third side is (a+b)(px + qy) = aq²- 2hpq + bp².