已知正方形
的边长为
,
为两条对角线的交点,如图所示,将Rt△BED沿BD所在的直线折起,使得点E移至点C,满足
.
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712413310828544/2714298242097152/STEM/fc4184ee-8031-4e69-8a0e-efa5bee11cf4.png?resizew=316)
(1)求四面体
的体积
;
(2)请计算:
①直线
与
所成角的大小;
②直线
与平面
所成的角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1d70676406f26d339465fe3473c0c05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712413310828544/2714298242097152/STEM/fc4184ee-8031-4e69-8a0e-efa5bee11cf4.png?resizew=316)
(1)求四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
(2)请计算:
①直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
②直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
2021·上海静安·二模 查看更多[3]
更新时间:2021-05-05 07:16:49
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相似题推荐
解答题-问答题
|
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名校
解题方法
【推荐1】已知直三棱柱
中,侧面
为正方形,
,E,F分别为
和
的中点,D为棱
上的点,
.
![](https://img.xkw.com/dksih/QBM/2022/5/30/2990386683256832/2991007382839296/STEM/bee3daa4-348a-4761-99c0-c52058f226e2.png?resizew=175)
(1)证明:
;
(2)求当面
与面
所成的二面角的正弦值最小时,三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f121eabff3c62c1a196d9ca5f6f83f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0023280949eda97787964f0a9d41ed2e.png)
![](https://img.xkw.com/dksih/QBM/2022/5/30/2990386683256832/2991007382839296/STEM/bee3daa4-348a-4761-99c0-c52058f226e2.png?resizew=175)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a7a3dc3f3a02f4400e22dec2f2fee23.png)
(2)求当面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af6c9a36e2ef7189317ae652c56e49c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba63c2da793db49e27248df750e6072d.png)
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【推荐2】如图,在四面体ABCD中,
,
,M是棱AD的中点.
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963550293278720/2965867278622720/STEM/ba51e16c-3524-4df5-8e2c-37d8da28260a.png?resizew=175)
(1)求四面体ABCD的表面积和体积;
(2)求直线CM与底面BCD所成的角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ad8bfb2f5d95ff00cc4ef8b7eb78883.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d783fe7f3ce673d5d21281174e7a7968.png)
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963550293278720/2965867278622720/STEM/ba51e16c-3524-4df5-8e2c-37d8da28260a.png?resizew=175)
(1)求四面体ABCD的表面积和体积;
(2)求直线CM与底面BCD所成的角的正弦值.
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【推荐1】如图,正方体
中,
,
、
分别是棱
与
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/520b5649-0ed7-494d-8b84-cdbc046d9b36.png?resizew=159)
(1)求异面直线
和
所成角的大小;
(2)求以
、
、
、
四点为四个顶点的四面体的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/520b5649-0ed7-494d-8b84-cdbc046d9b36.png?resizew=159)
(1)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c798204bbe306b3efd5bc9eae594c171.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e935bb9d7b7115429edbd1e7469af65.png)
(2)求以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6795cae2df43a722e1355e9562d93c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
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【推荐2】如图所示,在三棱柱
中,
是正方形
的中心,
,
平面
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/2/a04092ff-786e-4d47-ba45-042c4a507fa2.png?resizew=196)
(1)求异面直线
与
所成角的余弦值;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cf90bac174f02c4552e56df4d910bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1722a11031cf3668ac4a2abaca280cba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40f862a79ae6f3a1cc94884672a4d6a2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/2/a04092ff-786e-4d47-ba45-042c4a507fa2.png?resizew=196)
(1)求异面直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24aee5e085257d9a3b6169ac2d65ea00.png)
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【推荐1】 正四棱锥
中,
,求:直线
与平面
所成角的正弦值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f72900e99805cc33b49290b34fdea9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/696dd2d8ea51833b79ae5d6a1792514e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21665d21bbfb04410c78345de1fd15ae.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/c432164d-a57a-48b0-a2fe-85e8304787b4.png?resizew=190)
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解答题-证明题
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【推荐2】如图,在四棱锥
中,底面
是正方形,
平面
,
,点
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/1/60361ff2-2318-4ff9-a487-9a5a7b37637d.png?resizew=144)
(1)求证:
;
(2)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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e2942390d02efaff57473d103f7950a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/1/60361ff2-2318-4ff9-a487-9a5a7b37637d.png?resizew=144)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc55d282b5786fc0ac1fcf7e706e3a1.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f35614aff055b98b76ca262f64e629d.png)
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