连接P、Q并延长,使PQ与AD的延长线交于E
∵DQ=DC
∠DQE=∠CQP
∠EDQ=∠PCQ=RT∠
∴△EDQ≌△PCQ
∴ED=CP
AP=CD+CP AE=AD+ED
AD=CD
∴AE=AP
EQ=PQ
∴△AEQ≌△APQ
∴∠EAQ=∠PAQ
AQ平分∠DAP