复习题11AD=A′D′证明如下：∵△ABC≌△A′B′C′,所以AB=A′B′∠B=∠B′,BC=B′C′∵BD=(1/2)BC,B′D′＝（1/2）B′C′∴BD=B′D′在△ABD和△A′B′D′中,AB=A′B′,∠B=∠B′,BD=B′D′∴△ABD≌△A′B′D′（S...