如图四边形ABCD是边长为3的正方形,DE⊥平面ABCD,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/ddd1f18a-082d-40c3-985b-bd1e6b59f15d.png?resizew=163)
(1)求证:AC⊥平面BDE;
(2)若BE与平面ABCD所成角为
,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5852b8f3ecf394b98074432eafafbf84.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/ddd1f18a-082d-40c3-985b-bd1e6b59f15d.png?resizew=163)
(1)求证:AC⊥平面BDE;
(2)若BE与平面ABCD所成角为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/260200d547998bcac50a4a491382e7f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f717b7d4d0978eec7330afec554c078.png)
更新时间:2022-12-18 06:08:43
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【推荐1】在四棱锥P—ABCD中,平面PAB⊥平面ABCD,∠ABC=∠BCD=90°,PC=PD,PA=AB=BC=1,CD=2.
![](https://img.xkw.com/dksih/QBM/2021/12/22/2878188120391680/2917523442221056/STEM/fa3483a1-e42e-4020-99e1-f7c09afe43a2.png?resizew=185)
(1)证明:PA⊥平面ABCD;
(2)求点C到平面PBD的距离.
![](https://img.xkw.com/dksih/QBM/2021/12/22/2878188120391680/2917523442221056/STEM/fa3483a1-e42e-4020-99e1-f7c09afe43a2.png?resizew=185)
(1)证明:PA⊥平面ABCD;
(2)求点C到平面PBD的距离.
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【推荐2】如图,
是圆
的直径,点
是圆
上异于
,
的点,直线
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/22/cf64773d-a037-46c6-ab09-4036a5e13c24.png?resizew=175)
(1)证明:平面
平面
;
(2)设
,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/22/cf64773d-a037-46c6-ab09-4036a5e13c24.png?resizew=175)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19e0ba32fcadd4114a3c52b52c3aea23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29e240a6378adf6d23ebf9cc710c9bd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12a4bddf1ea3c5d37f2233a4821909e9.png)
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【推荐3】如图所示的几何体中,
为三棱柱,且
平面
,四边形
为平行四边形,
,
.
(1)若
,求证:
平面
;
(2)若
,
,二面角
的余弦值为
,求三棱锥
的体积.
![](https://img.xkw.com/dksih/QBM/2016/7/1/1572857765330944/1572857771720704/STEM/edd5ecfd6b734c19969eebb2244be837.png?resizew=176)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42b730d87bb95763a48c69f1b0329ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a58a622e2b1a239f2f96aa1501e9799.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46fe926770d2354e172dec02f5ce2efe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d1d2e0f281222a5f289ea4008370aed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fb04914c4e8fb3483da44c67fe1809f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/833cfda415649b832cc136caed392753.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb8b7dbd627b58c8b75edb37a61a5e15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35d027be176d18651cfd30f5492789ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dcecfc88e45465b7e2215a8557148da.png)
![](https://img.xkw.com/dksih/QBM/2016/7/1/1572857765330944/1572857771720704/STEM/edd5ecfd6b734c19969eebb2244be837.png?resizew=176)
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【推荐1】已知直三棱柱
中,
是边长为2的等边三角形,
,
为
的中点.
平面
;
(2)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55a2310cbba5e050488cd9296eb195d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4cc24037ff3b29f2cb81291734869d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ba9e20d667d04bf3ee7f55cc795ce01.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ba9e20d667d04bf3ee7f55cc795ce01.png)
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【推荐2】已知三棱柱
,
是正三角形,四边形
是菱形且
,
是
的中点,
.
![](https://img.xkw.com/dksih/QBM/2021/4/10/2696684447408128/2730855733706752/STEM/3bbd6269-45ff-4c76-84c9-3e050ded9fd2.png?resizew=235)
(1)证明:
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7e3c9e7c05de9838c0c5d762720d3ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cead256658d6f874b3b298f8dd2c055.png)
![](https://img.xkw.com/dksih/QBM/2021/4/10/2696684447408128/2730855733706752/STEM/3bbd6269-45ff-4c76-84c9-3e050ded9fd2.png?resizew=235)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed46a014ece6a0830c7c8b8deb2c56e0.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
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【推荐3】如图,三棱柱
中,
,侧面
为矩形,
,二面角
的正切值为
.
(1)求侧棱
的长;
(2)侧棱
上是否存在点
,使得平面
与平面
所成的锐二面角的余弦值为
?若存在,判断
点的位置并证明;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26c40bccd2075cf8504ddfe1d31d41b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc5b398965f6cefede6b94469b5b71d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/524931a902bacd35904905b0a12a947c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/13/151ce16b-f4e3-4048-b6ab-420aeffccfd0.png?resizew=172)
(1)求侧棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
(2)侧棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16be0d639969598b638d1b6170bd1689.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b2215de6d4986954c95a5b711fd05aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
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【推荐1】如图所示多面体
中,四边形ABCD和四边形ACEF均为正方形,棱
,G为EF的中点.
平面ABCD;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2fc1129846f37afdafd751627c450d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e39b13d187b25461d85a3b8d10c7b678.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b190c8d3d7d7d0e6e959e8a52eae90.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/522f9c221ae35f902c2f5d9f7d4b9a32.png)
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【推荐2】如图,四边形ABCD为平行四边形,点E在AB上,AE=2EB=2,且DE⊥AB,沿DE将
折起,使点A到达点F的位置,且
.
![](https://img.xkw.com/dksih/QBM/2022/5/8/2975183986835456/2976180750860288/STEM/cde9e36c-992a-4b9e-b701-d7262b4f5b8c.png?resizew=270)
(1)求证:平面BFC⊥平面BCDE;
(2)若直线DF与平面BCDE所成的角的正切值为
,求平面DEF与平面DFC的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ffcd654e4bf0e87eecf234944443200.png)
![](https://img.xkw.com/dksih/QBM/2022/5/8/2975183986835456/2976180750860288/STEM/cde9e36c-992a-4b9e-b701-d7262b4f5b8c.png?resizew=270)
(1)求证:平面BFC⊥平面BCDE;
(2)若直线DF与平面BCDE所成的角的正切值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83303d3784492506fc44f2b4d6b07bc1.png)
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【推荐3】在如图所示的几何体中,四边形ABCD是边长为2的菱形,∠DAB=60°,DE⊥平面ABCD,AF∥DE,且AF=
DE.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/754f5171-865e-47bc-86fa-ae1e6e822dd6.png?resizew=180)
(1)证明:AC⊥BE;
(2)若DE=6,求二面角F-BE-D的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/754f5171-865e-47bc-86fa-ae1e6e822dd6.png?resizew=180)
(1)证明:AC⊥BE;
(2)若DE=6,求二面角F-BE-D的余弦值.
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