Let P and Q be points inside triangle ABC satisfying ∠PAC=∠QAB and ∠PBC=∠QBA.a) Prove that feet of perpendiculars from P and Q on the sides of triangle ABC are concyclic. b) Let D and E be feet of perpendiculars from P on the lines BC and AC and F foot of perpendicular from Q on AB. Let M be intersection point of DE and AB. Prove that MP⊥CF. geometrycircumcircleradical axisgeometry proposed