写清格式.图上有做辅助线的方法.
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/06 00:33:02
写清格式.图上有做辅助线的方法.
![](http://img.wesiedu.com/upload/8/5c/85c3639504dd58d9e2344cc93563d471.jpg)
![](http://img.wesiedu.com/upload/8/42/842cb29e5a5aed64a5f5a3b7b63ec13a.jpg)
![](http://img.wesiedu.com/upload/8/5c/85c3639504dd58d9e2344cc93563d471.jpg)
![](http://img.wesiedu.com/upload/8/42/842cb29e5a5aed64a5f5a3b7b63ec13a.jpg)
![写清格式.图上有做辅助线的方法.](/uploads/image/z/18117277-61-7.jpg?t=%E5%86%99%E6%B8%85%E6%A0%BC%E5%BC%8F.%E5%9B%BE%E4%B8%8A%E6%9C%89%E5%81%9A%E8%BE%85%E5%8A%A9%E7%BA%BF%E7%9A%84%E6%96%B9%E6%B3%95.)
延长CB到G,使BG=DF,由于AB=AD,∠D=∠ABG=90°所以:RT△ABG≌RT△ADF所以:AG=AF,∠DAF=∠BAG所以:∠FAG=∠DAB由∠EAF=(1/2)∠DAB得:∠EAF=(1/2)∠FAG所以:∠FAE=∠GAE所以:由AG=AF,AE=AE,∠FAE=∠GAE得△AGE≌△AFE所以:EF=EG而:EG=GB+EB=DF+EB所以:EF=DF+BE ![](http://img.wesiedu.com/upload/a/a8/aa8ef19fb2c0dc0caacc44b4d5328f87.jpg)
![](http://img.wesiedu.com/upload/a/a8/aa8ef19fb2c0dc0caacc44b4d5328f87.jpg)