最好有詳細的分析過程,謝謝.
熱心網友
因為BD=1/3AB=1/4AD所以AB=3BD；AD=2BD；DC=4BDEB=1/2AB=3/2BD；DF=1/2DC=2BD；BF=BDEF=EB+BF=5/2BD因為EF=10cm，所以5/2BD=10cm，BD=4cmCD=4BD=16cm
熱心網友
設BD=X，則AB=3X，CD=4X，BE=1.5X,DF=2X;BF = DF - BD =X;則EF= BE - BF =0.5X =10;X=20;則CD =80.
最好有詳細的分析過程,謝謝.
因為BD=1/3AB=1/4AD所以AB=3BD；AD=2BD；DC=4BDEB=1/2AB=3/2BD；DF=1/2DC=2BD；BF=BDEF=EB+BF=5/2BD因為EF=10cm，所以5/2BD=10cm，BD=4cmCD=4BD=16cm
設BD=X，則AB=3X，CD=4X，BE=1.5X,DF=2X;BF = DF - BD =X;則EF= BE - BF =0.5X =10;X=20;則CD =80.