Forgot password?
 Register account
View 335|Reply 4

[几何] 平面几何求线段长

[Copy link]

277

Threads

547

Posts

5413

Credits

Credits
5413

Show all posts

力工 Posted 2022-10-5 16:36 |Read mode
Last edited by 力工 2022-10-5 16:51这是看到的一道中考题,据说深圳的填空题,这题我表示不容易。发出来,求教大佬的高招。
已知直角$\triangle ABC$中,两直角边$AB=3,BC=5$.线段$AE=2\sqrt{5},\triangle CDE$是以$CE$为斜边的等腰直角三角形,点$F$在线段$AE$上,且$\angle DBF=45\du $,求$AF$的长。(结果$\frac{3\sqrt{5}}{4}$)
QQ图片20221005163247.png

3

Threads

9

Posts

168

Credits

Credits
168

Show all posts

exctttt Posted 2022-10-6 08:21
果然可以旋转相似
[S3J${)(Z2B1LJ[(1JWI96M.png

Rate

Number of participants 1威望 +1 Collapse Reason
力工 + 1 赞一个!

View Rating Log

277

Threads

547

Posts

5413

Credits

Credits
5413

Show all posts

 Author| 力工 Posted 2022-10-6 17:25
大佬们,各自都来炫一个

277

Threads

547

Posts

5413

Credits

Credits
5413

Show all posts

 Author| 力工 Posted 2022-10-11 13:01
看来大佬们兴趣不大,我用向量或坐标法好像也进行不了。

277

Threads

547

Posts

5413

Credits

Credits
5413

Show all posts

 Author| 力工 Posted 2022-10-11 14:01
力工 发表于 2022-10-11 13:01
看来大佬们兴趣不大,我用向量或坐标法好像也进行不了。
用正余弦定理也是一头雾水。

Mobile version|Discuz Math Forum

2025-5-31 11:18 GMT+8

Powered by Discuz!

× Quick Reply To Top Edit