来自傅惠的问题
如图,在△ABC中,AB=4cm,AC=2cm,在AB上取一点D,当AD=______cm时,△ACD∽△ABC.
如图,在△ABC中,AB=4cm,AC=2cm,在AB上取一点D,当AD=______ cm时,△ACD∽△ABC.


如图,在△ABC中,AB=4cm,AC=2cm,在AB上取一点D,当AD=______cm时,△ACD∽△ABC.
如图,在△ABC中,AB=4cm,AC=2cm,在AB上取一点D,当AD=______ cm时,△ACD∽△ABC.
如图,∵∠A=∠A,
∴当ADAC