急一道超难数学题如图,四边形ABCD是菱形,∠A=60°,直线EF经过点C,分别交AB、AD的延长线于E、F两点,连接E

2个回答

  • (1) ∠DBE=∠BDF=120°

    BE/AB=CE/CF=BE/BD

    AD/DF=CE/CF=BD/DF

    △BDE∽△DFB

    BE/DB=BD/DF

    BE/3=3/2

    BE=4.5

    (2)△BDE∽△DFB

    ∴BE/DB=BD/DF

    BE/DB=BE/BC

    BD/DF=DC/DF

    ∴BE/BC=DC/DF,∠EBC=∠FDC=60

    ∴△BEC∽△DCF

    (3)△BDE∽△DFB

    ∠BED=∠DBF

    又∠BDE=∠HDB

    △BDE∽△HDB

    DE/BD=BD/DH

    BD^2=DH*DE