如图,直线AB、CD相交于点O,角DOE:角BOE=4:1,OF平分角AOD,角AOC-角AOF=角AOF-15°,求角EOF的度数.

问题描述:

如图,直线AB、CD相交于点O,角DOE:角BOE=4:1,OF平分角AOD,角AOC-角AOF=角AOF-15°,求角EOF的度数.

无图无真相,一楼大神啊...=。=

我的题目和你的有一点不一样

角AOC=180-2角AOF,故由等式可知: 180-3角AOF=角AOF-15 =>角AOF=DOF=41.25
可求出角 AOD=82.5, DOB=180-82.5=97.5, DOE=4/5DOB=78,EOF=EOD+FOD=78+41.25=119.25

图呢?

因为OF平分角AOD,所以角AOF=角DOF=角AOC+15°
因为角COD=180°,角AOC+角AOF+角DOF=角COD=180°,3角AOC+30°=180°,所以角AOC=50°
又因为角DOF=65°,所以角AOC=角BOD=50°,角DOE=40°,角EOF=65°+40°=105°

因为OF平分角AOD,那么角AOF=DOF=AOC+15°
COD=180°,AOC+AOF+DOF=COD=180°,3AOC+30=180,AOC=50
DOF=65,AOC=BOD=50,DOE=40,EOF=65+40=105