证明:两边及其中一边的对角(钝角
已知:如图,在△ABC,△A'B'C'中,AC=A'C',BC=B'C'。 ∠B=∠B'>90°
求证:△ABC≌△A'B'C'
证明:
作CD⊥AB于D,(∠ABC>90,D一定在AB延长线上),C'D'⊥A'B'于D'
∠ABC=∠A'B'C'==>∠CBD=∠C'B'D'
∠D=∠D'=90°
BC=B'C'
==>△CBD≌△C'B'D'
==>BD=B'D',CD=C'D'
AC=A'C'
==>Rt△ACD≌Rt△A'C'D'
==>AD=A'D'
==>AB=A'B'
BC=B'C'
∠ABC=∠A'B'C'
==>△ABC≌△A'B'C'。全部
已知:如图,在△ABC,△A'B'C'中,AC=A'C',BC=B'C'。
∠B=∠B'>90°
求证:△ABC≌△A'B'C'
证明:
作CD⊥AB于D,(∠ABC>90,D一定在AB延长线上),C'D'⊥A'B'于D'
∠ABC=∠A'B'C'==>∠CBD=∠C'B'D'
∠D=∠D'=90°
BC=B'C'
==>△CBD≌△C'B'D'
==>BD=B'D',CD=C'D'
AC=A'C'
==>Rt△ACD≌Rt△A'C'D'
==>AD=A'D'
==>AB=A'B'
BC=B'C'
∠ABC=∠A'B'C'
==>△ABC≌△A'B'C'。收起