解题方法
1 . 如图,三棱柱
中,
平面ABC,AB=3,AC=4,BC=5.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/adec8e1a-65cb-4a6e-a6f7-a4d44378610c.png?resizew=143)
(1)求证:
平面
;
(2)若异面直线
与
所成的角为30°,求三棱柱
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/29/adec8e1a-65cb-4a6e-a6f7-a4d44378610c.png?resizew=143)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
(2)若异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ee8456443402a25b1e25d35ff7e1c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
您最近一年使用:0次
解题方法
2 . 如图,在正方体
中,
、
分别为
、
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/17/183e2390-544e-4e27-b88d-f818d47be664.png?resizew=161)
(1)求证:
;
(2)求证:
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c08f80a9b38074366fd7a0151ff143d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2657191a56c0a9deb864763498935706.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/17/183e2390-544e-4e27-b88d-f818d47be664.png?resizew=161)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02a0e00113872f921116b6c0c3177d0f.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ae72f5e5891249caa10c43224da89c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3c241f900cb6ed341c137a3d71216a4.png)
您最近一年使用:0次