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AD//EF//GH//BC,AE=EG=GB,AD=3,BC=6,则EF等于?
A3.5 B4 C4.5 D480
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人气:389 ℃ 时间:2020-04-10 18:18:25
解答
连接AC,交EF于M∵AD//EF//GH//BC,AE=EG=GB∴DF=FH=HC(平行线等分线段定理)∴AE/AB=1/3,CF/CD=2/3∵EF∥BC∴△AEM∽△ABC∴EM/BC=AE/AB=1/3EM=1/3BC=1/2×6=2同理△CFM∽△ACD∴MF/AD=CF/CD=2/3MF=2/3AD=2/3×3=2∴...
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