转动36060=6。;设经过x分钟分针与吋针重合,则有:6x・0.5x=240,解得:x=——分钟;11即8点与9点Z间,分针与时针重合的时刻是8点—分。1124.解:Toe平分Zaob,of平分Zboc,Zboc,AZBOE=-ZAOB=1x90°=45°,ZCOF=ZBOF=2*VZBOF=ZEOF-ZBOE=60°-45°=15°,/.ZBOC=2ZBOF=30o;ZAOC=ZBOC+ZAOB=30o+90o=120°25.解:VZBOC=2ZBOD,AZCOD=ZBOC+ZBOD=3ZBOD,VOD平分ZAOC,/•ZAOD=ZCOD=3ZBOD,/.ZA0B=ZA0D+ZB0D=4ZB0D,ZAOB=90°,/.4ZBOD=90°,AZB0D=22.5o.26.(1)解:TOC是ZAOD的平分线,OE是ZBOD的平分线,?AZDOE=|ZBOD,ZCOD=\Zaod,vaob是一条直线,/.ZAOB=180°,1?1?1?'AZCOE=ZDOE+ZCOD=?-?ZBOD+?-ZAOD=?一?(ZBOD+ZAOD)=?-ZAOB=90°,0?3?7■・•・ZAOC=ZAOE・ZEOC=140°・90°=50°(2)解:由(1)可知ZEOC=90°,VZEOD:ZCOD=2:3,・•・可设ZEOD=2x°,ZCOD=3x°,/.2x+3x=90,解得x=18,/.ZCOD=3x°=54°27.(1)解:・.・0E平分ZAOC,・・.ZAOE=ZEOC=*ZAOO|x48°=24°,AZBOE=180°-ZAOE=180°-24°=156°(2)解:OD平分ZBOC.理由如下:VZDOE=90°,ZEOC=24°,・\ZDOC=ZDOE-ZEOC=90°-24°=66°.VZB0D=ZB0E-ZD0E=156o-90°=66\/.ZDOC=ZBOD,/.OD平分ZBOC
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