如图,AB=CD,AE=CD,BO=DO,EO=FO,求证:OC=OA
如图,AB=CD,AE=CD,BO=DO,EO=FO,求证:OC=OA
如图,AB、CD相交于点O,∠A=∠C,EO=FO,∠1=∠2,试说明:DO=BO.
已知,如图,AB=CD,OA=OD,OB=OC,求证:AB∥CD.
如图,AB=CF,AE=CF,BO=DO,EO=FO,试说明角B=角D
如图,已知AC,BD交于点O,AB平行CD,OA=OC,求证AB=CD
如图,AB,CD相交于点O,AC||BD,求证OA*OD=OB*OC
已知,如图9,AB=CD,AD=BC,EF交DC于E,交AB于F,O为AC中点,求证EO=FO
如图AB=CD,BE=CF,AE=DF求证OA=OD
如图,已知ABⅡCD,OA=OD,AE=DF,求证:BEⅡCF.
已知如图,E.F在BD上,且AB=CD,BF=DE,AE=CF,求证:OA=OC.OB=OD
已知:如图,平行四边形ABCD中,点E,F分别在CD,AB上,DF∥BE,EF交BD于点O,求证:EO=FO
(2010•朝阳区二模)已知,如图,AC与BD交于点O,AO=OC,BO=DO.求证:AB∥CD.