如图,AD和BC相交于点O,OA=OD,OB=OC.求证AB平行DC?
如图,AD和BC相交于点O,OA=OD,OB=OC.求证AB平行DC?
如图,AC和BD相交于点O,且AB平行DC,OC=OD,求证:OA=OB
如图:AC和BD相交于点O,OA=OC,OB=OD,求证:DC//AB
已知:如图,AB平行CD,AD与BC相交于点O,且OA=OD.求证OB=OC
已知:如图ab平行于cd,ab等于dc,ad与bc交于o点,求证:oa=od,ob=oc
如图,AB,CD相交于点O,且OA*OD=OB*OC,求证AC平行DB
已知:如图,AD与BC相交于点O,OA=OD,OB=OC.求证:
已知,如图,AC,BD交于O点,且OA=OC,OB=OD.求证:AB平行CD,AD平行BC.
已知:如图,AB与CD相交于点O,且OA=OD,OB=OC 求证:AD平行CB
如图,AB,CD相交于点O,AC||BD,求证OA*OD=OB*OC
如图,AC和BD相交于点O,且AB∥DC,OC=OD,求证:OA=OB.
数学题:如图,OA=OB,OC=OD,AD和BC相交于点P.