This website requires JavaScript.
Explore
Help
Register
Sign In
huanghai
/
python
Watch
1
Star
0
Fork
0
You've already forked python
Code
Issues
Pull Requests
Actions
Packages
Projects
Releases
Wiki
Activity
Files
main
python
/
数学课程
/
【2022河南中考题】动点隐藏圆,面积任你玩.md
HuangHai
1f397eca87
'commit'
2025-08-30 18:35:01 +08:00
567 B
Raw
Permalink
Blame
History
直角三角形,斜边中线,等于斜边一半
BG=\frac{1}{2}EF=2
$BG$长度固定,则$G$在以$B$为圆心,长度为$2$的圆上运动
四边形面积最小,可以看成上面的三角形$ACD$是固定值,只要$\triangle AGC$面积最小即可,从$G$向$AC$引垂线,则
S_{\triangle AGC}=\frac{1}{2}AC\times GM
$GM$什么时候最短呢?
GM>=BM-BG>=BH-BG
所以求出$BH$即可,按面积相等求解吧