27.如圖1至圖2,點(diǎn)A為射線OM上一定點(diǎn),點(diǎn)P、Q是直線ON上的兩動(dòng)點(diǎn),點(diǎn)Q在點(diǎn)P的右側(cè),且PQ=OA,點(diǎn)B為∠MON的平分線OF所在直線上一動(dòng)點(diǎn),BA=BP.
探究一:若PQ在射線ON上,∠ABP與∠MON互補(bǔ):
(1)∠BAO+∠BPO=
°;
(2)如圖1,當(dāng)P為OQ中點(diǎn)時(shí),∠OAB=
°;
(3)如圖2,當(dāng)OP≠PQ時(shí),求證:點(diǎn)B在線段OQ中垂線上.
探究二:若∠MON=120°,且點(diǎn)B在線段OQ中垂線上,點(diǎn)C為線段OQ中點(diǎn),連接BC,若∠PBC=α,則用含α的代數(shù)式表示∠ABO=
.