∴
FD |
BC |
AF |
AC |
FD |
3 |
4?FD |
4 |
解得:FD=
12 |
7 |
圖2中,過(guò)點(diǎn)C作CM⊥AB于點(diǎn)M,如圖所示:
![](http://hiphotos.baidu.com/zhidao/pic/item/14ce36d3d539b600531ed506ea50352ac75cb7ab.jpg)
CM=
AC×BC |
AB |
12 |
5 |
∵GF∥AB,
∴
CN |
CM |
GF |
AB |
x |
5 |
| ||
|
解得:x=
60 |
37 |
∵
12 |
7 |
60 |
37 |
∴甲同學(xué)的設(shè)計(jì)方案符合要求.
FD |
BC |
AF |
AC |
FD |
3 |
4?FD |
4 |
12 |
7 |
AC×BC |
AB |
12 |
5 |
CN |
CM |
GF |
AB |
x |
5 |
| ||
|
60 |
37 |
12 |
7 |
60 |
37 |