Let t seconds pass, PQ and circle O are both at point E. At this time, AP = TCQ = 2tbq =15-2tpd =13-t According to the tangent length theorem, PE = PA QE = QB∴ PQ = 15-t is the parallel line passing through point A. 5 +BF？ 0? 5 = PQ？ 0? 5 can list the equation about t, the chief of AB should have told you, right?