已知正四棱柱
,
,
分别是棱
的中点.
(1)求异面直线
与
所成角的大小;
(2)求四面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08be4b2d4df629c42b06ad693b8a44cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7835c72d14f9d61b95b15aa47fafac2.png)
(1)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
(2)求四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85d07987bdefb56d62ee39f17cb19af1.png)
更新时间:2020-01-11 14:34:04
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图所示:在五面体ABCDEF中,四边形EDCF是正方形,AD=DE=1,∠ADE=90°,∠ADC=∠DCB=120°.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/bdfc65fd-ed2e-4f87-ba3b-23b6982fc0d5.png?resizew=178)
(Ⅰ)求证:平面ABCD⊥平面EDCF;
(Ⅱ)求三棱锥A-BDF的体积.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/bdfc65fd-ed2e-4f87-ba3b-23b6982fc0d5.png?resizew=178)
(Ⅰ)求证:平面ABCD⊥平面EDCF;
(Ⅱ)求三棱锥A-BDF的体积.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐2】如图,已知AB是半圆O的直径,C为
上一动点,
平面ABC,D为弦AC的中点.
(1)证明:
平面PAC.
(2)若
,三棱锥
的体积为
,指出C的位置,并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/3/96ebc839-70c6-491e-b81e-41991d849829.png?resizew=170)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02cbddc9b1f36e2cabd9a6c830d14736.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9a4950a6e4202efd609507964af238b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/426f883d7df8415511742145c7d9ba91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18483c9c195ecd922772527fa85c0fcb.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐1】已知三棱柱ABCA1B1C1的侧棱长和底面边长均为2,A1在底面ABC内的射影O为底面三角形ABC的中心,如图所示.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/21/5a6dd505-17d4-4a5b-ab1d-126d4739767c.png?resizew=170)
(1)连接BC1,求异面直线AA1与BC1所成角的大小;
(2)连接A1C,A1B,求三棱锥C1BCA1的体积.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/21/5a6dd505-17d4-4a5b-ab1d-126d4739767c.png?resizew=170)
(1)连接BC1,求异面直线AA1与BC1所成角的大小;
(2)连接A1C,A1B,求三棱锥C1BCA1的体积.
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐2】在四棱锥
中,底面是边长为
的菱形,对角线
与
相交于点
,
,
平面
,平面
与平面
所成的角为45°,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/43c1b69f-2949-4db8-9976-b44038b16f7b.png?resizew=216)
(1)证明:平面
平面
;
(2)求异面直线
与
所成角的余弦值;
(3)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6e0b64d25ddd18454f88e40c45d7d8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.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/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/43c1b69f-2949-4db8-9976-b44038b16f7b.png?resizew=216)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(2)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
(3)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
您最近一年使用:0次