名校
解题方法
1 . 中国古代数学名著《九章算术》中,将四个面都为直角三角形的三棱锥称之为“鳖臑”,若三棱锥
为鳖臑,
平面
,
,
,则结论正确的序号是______ .(填写序号即可)
①
平面
;
②直线
与平
所成角的正弦值为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5ec70bc9d4f8f5df312e2f09ee3bcb5.png)
③二面角
的余弦值为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3fa3ba9c03ed22792d22d01518fcf40.png)
④三棱锥
外接球的表面积为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/491c3a4f72b84ebadd28b90711435adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/209acf15985d1ea1ad86fc4a37e38c0b.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
②直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5ec70bc9d4f8f5df312e2f09ee3bcb5.png)
③二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3fa3ba9c03ed22792d22d01518fcf40.png)
④三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f1dd170ff8de46ede27254c7b70f2f.png)
您最近一年使用:0次
解题方法
2 . 从棱长为1的正方体
八个顶点中取不共面的四个顶点构成一个三棱锥,则下列关于该三棱锥说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
A.该三棱锥可能为正四面体 | B.该三棱锥的四个面可以均为直角三角形 |
C.所有三棱锥的体积均相同 | D.该三棱锥的外接球表面积为![]() |
您最近一年使用:0次