在CAD中,选择cad软件菜单栏的画直线选项,在画直线时按住Shift键,然后画斜线,画出来的线就是45度的线。
工程制图中三面投影45度斜线的作用主要是用来定宽相等,即俯视图与左视图一定要宽相等,通过45度斜线来作比较方便。
当然, 俯视图与左视图要宽相等,也可以用圆规划圆来作。
1、打开cad,画一条直线跟一条辅助线。延伸功能基本上都需要一条辅助线来帮助完成
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/a71ea8d3fd1f4134c4f2611a351f95cad0c85e88?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
2、输入延伸命令“ex”
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/32fa828ba61ea8d3ace71060870a304e241f5888?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
3、按空格键确认,出现选择目标
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/bd3eb13533fa828be9e6f987ed1f4134960a5a88?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
4、选择要延伸到的目标,本经验选择点击下面的横线
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/838ba61ea8d3fd1f13ccc65e204e251f94ca5f88?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
5、按空格键完成目标选取以及切换到选择要延伸的目标
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/b03533fa828ba61ef82bac4b5134970a314e5988?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
6、选择要延伸的目标,完成延伸操作。如图所示
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/a9d3fd1f4134970a64b6744b85cad1c8a6865d88?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)