如圖所示,∠AOB是平角,OM、ON分別是∠AOC、∠BOD的平分線.
(1)當(dāng)∠BOC=140°時(shí),求∠AOM的度數(shù);
(2)當(dāng)∠AOC=30°,∠BOD=60°時(shí),求∠MON的度數(shù);
(3)當(dāng)∠COD=x度時(shí),則∠MON=(? ? )度.(請直接寫出答案)

如圖所示,∠AOB是平角,OM、ON分別是∠AOC、∠BOD的平分線.
(1)當(dāng)∠BOC=140°時(shí),求∠AOM的度數(shù);
(2)當(dāng)∠AOC=30°,∠BOD=60°時(shí),求∠MON的度數(shù);
(3)當(dāng)∠COD=x度時(shí),則∠MON=(? ? )度.(請直接寫出答案)