11-12高二上·北京·期末
1 . 如图,正四面体
的顶点A、
、
分别在两两垂直的三条射线
、
、
上,给出下列四个命题:
①多面体
是正三棱锥;
②直线
平面
;
③直线
与
所成的角为
;
④二面角
为
.
其中真命题有_______________(写出所有真命题的序号).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3e5af20b2f8c1fba4470f9650989e51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b14069d21d32c724f0ebe3e311f114c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5615812990deef255366042987977c58.png)
①多面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4278c0911e7df78965e78cff69cac5f5.png)
②直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d38e752c16ae27d35378a765172022b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
③直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e5fa72f2878b476bc57f0df12d6555.png)
④二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1f3fddfd6bcc5cf2d6bb501fae6486b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e5fa72f2878b476bc57f0df12d6555.png)
其中真命题有_______________(写出所有真命题的序号).
![](https://img.xkw.com/dksih/QBM/2011/3/9/1570032614424576/1570032619610112/STEM/5b49a6527cc747748bb96cf4b50b5a0a.png?resizew=286)
您最近一年使用:0次
2 . 如图,正方体
中,
,
分别为 棱
,
上的点. 已知下列判断:
![](https://img.xkw.com/dksih/QBM/2011/2/10/1569979979890688/1569979985092608/STEM/abe71c74840040f8bcfdde4a3b6dcba4.png?resizew=212)
①
平面
;②
在侧面
上 的正投影是面积为定值的三角形;③在平面
内总存在与平面
平行的直线;④平 面
与平面
所成的二面角(锐角)的大小与点
的位置有关,与点
的位置无关.
其中正确判断的个数有
![](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/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/2011/2/10/1569979979890688/1569979985092608/STEM/abe71c74840040f8bcfdde4a3b6dcba4.png?resizew=212)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d26d8a9d64ad3c8cba28840b41ed7837.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/589c878e789e07e33d65c8a18cf2c58a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/913f45fae2d284b17d1acaf70efa13d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/589c878e789e07e33d65c8a18cf2c58a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/589c878e789e07e33d65c8a18cf2c58a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
其中正确判断的个数有
A.1个 | B.2个 | C.3个 | D.4个 |
您最近一年使用:0次