来自胡绳荪的问题
如图,BD是∠ABC的平分线,DE⊥AB于E,S△ABC=36cm2,AB=18cm,BC=12cm,则DE的长是()A.2cmB.4cmC.1.2cmD.2.4cm
如图,BD是∠ABC的平分线,DE⊥AB于E,S△ABC=36cm2,AB=18cm,BC=12cm,则DE的长是()
A.2cm
B.4cm
C.1.2cm
D.2.4cm


如图,BD是∠ABC的平分线,DE⊥AB于E,S△ABC=36cm2,AB=18cm,BC=12cm,则DE的长是()A.2cmB.4cmC.1.2cmD.2.4cm
如图,BD是∠ABC的平分线,DE⊥AB于E,S△ABC=36cm2,AB=18cm,BC=12cm,则DE的长是()
A.2cm
B.4cm
C.1.2cm
D.2.4cm
如图,过点D作DF⊥BC于F,
∵BD是∠ABC的平分线,DE⊥AB,
∴DE=DF,
∵AB=18cm,BC=12cm,
∴S△ABC=12