sin∠DBC=CD/BC=2/7
设CD=2x 则 BC=7x 则AC=2CD = 4x
△ABC的周长 = AB+BC+AC =18x=18
则 x=1 即 AC = 4 CD=2 BC=7
BD=3根号5
△ABC的面积 = (ACxBD)/2=6根号5
sin∠DBC=CD/BC=2/7
设CD=2x 则 BC=7x 则AC=2CD = 4x
△ABC的周长 = AB+BC+AC =18x=18
则 x=1 即 AC = 4 CD=2 BC=7
BD=3根号5
△ABC的面积 = (ACxBD)/2=6根号5