解:(1)正确画出图形………………………………………….…………..1分
. ……………………………………………2分 证明:如图(1),在直线 上截取 ,连结 .
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104125654-62925.gif)
, , .
, .
, , .
, .·························· 3分
, .……………………………4分
, .
.又 ,
.
.
.………… ………….………………………………..5分 (2) . 说明:如图(2),过点 作 , ,垂足为 .
![](http://img.shitiku.com.cn/uploads/allimg/20191104/20191104125701-97826.gif)
.
, ,
.
四边形 为矩形.
, .
,
.
.·············································································· 6分
. . 在 和 中, ,
.………………………………………………………………………………7分 |