The girl's information(信息)
First name: _____________
Last name ___________
School: No.6 Middle School
Class: _______, Grade: 7
Phone number: 82506372
School ID card number: ___________
Favorite color: ____________
_______ do you usually deal _______ your old clothes?
如图,点C在线段BD上,AC⊥BD,CA=CD,点E在线段CA上,且满足DE=AB,连接DE并延长交AB于点F.
(1)求证:DE⊥AB;
(2)若已知BC=a,AC=b,AB=c,设EF=x,则△ABD的面积用代数式可表示为;S∆ABD=12cc+x你能借助本题提供的图形,证明勾股定理吗?试一试吧.
— It's dangerous to swim in this river.
—Yes, you are right. The government has ______ people not to swim in it.