已知如图正四面体
的侧面积为
,
为底面正三角形
的中心.
![](https://img.xkw.com/dksih/QBM/2017/2/6/1619486499913728/1619486500413440/STEM/c9f16c7051e0464b93334e327ca18519.png)
(1)求证:
;
(2)求点
到侧面
的距离.
![](https://img.xkw.com/dksih/QBM/2017/2/6/1619486499913728/1619486500413440/STEM/7e67463512724d7cbd29218e5705b4ad.png)
![](https://img.xkw.com/dksih/QBM/2017/2/6/1619486499913728/1619486500413440/STEM/8e6e21a97fa447b0872c6c22258b575e.png)
![](https://img.xkw.com/dksih/QBM/2017/2/6/1619486499913728/1619486500413440/STEM/913e5e17d6d94847b9d410a0f03f6a85.png)
![](https://img.xkw.com/dksih/QBM/2017/2/6/1619486499913728/1619486500413440/STEM/3d916c7919354aeea0023eae22fbeeb6.png)
![](https://img.xkw.com/dksih/QBM/2017/2/6/1619486499913728/1619486500413440/STEM/c9f16c7051e0464b93334e327ca18519.png)
(1)求证:
![](https://img.xkw.com/dksih/QBM/2017/2/6/1619486499913728/1619486500413440/STEM/69fc11716971402c90036d148af4141d.png)
(2)求点
![](https://img.xkw.com/dksih/QBM/2017/2/6/1619486499913728/1619486500413440/STEM/913e5e17d6d94847b9d410a0f03f6a85.png)
![](https://img.xkw.com/dksih/QBM/2017/2/6/1619486499913728/1619486500413440/STEM/7e67463512724d7cbd29218e5705b4ad.png)
更新时间:2017-02-08 11:56:37
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相似题推荐
解答题-证明题
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解题方法
【推荐1】如图,已知在直三棱柱
中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/3f900df2-63f5-4788-8e3d-bbcf1dd6e724.png?resizew=135)
(1)若
,求证:
平面
;
(2)若在底面△
中,
,点
为线段
上一点,满足三棱锥
的体积为
,求线段
的长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46fe926770d2354e172dec02f5ce2efe.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/3f900df2-63f5-4788-8e3d-bbcf1dd6e724.png?resizew=135)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d1d2e0f281222a5f289ea4008370aed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
(2)若在底面△
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c01138acca46627f2dc26aeb95b4da9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66bcd37c24ab163adff90c9c0caaa4b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827ccf0c04aa941ba20d5f4c6068b46b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
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解答题-证明题
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【推荐2】在如图所示的多面体中,ABCD是正方形,A,D,E,F四点共面,AF∥面CDE.
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712384289480704/2718280504639488/STEM/96f57ed87c0948acaa572d7fa3c76928.png?resizew=158)
(1)求证:BF∥面CDE;
(2)若AD=DE=3,AF=1,
,求证:AD⊥平面CDE.
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712384289480704/2718280504639488/STEM/96f57ed87c0948acaa572d7fa3c76928.png?resizew=158)
(1)求证:BF∥面CDE;
(2)若AD=DE=3,AF=1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/533205f32369f31adfeba25dfd422955.png)
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解答题-证明题
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较易
(0.85)
解题方法
【推荐1】四棱锥P﹣ABCD中,AB∥CD,AB⊥BC,AB=BC=1,PA=CD=2,PA⊥平面ABCD,E在棱PB上.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/23e72e83-7552-4255-8d8c-b896597251fd.png?resizew=261)
(Ⅰ)求证:AC⊥PD;
(Ⅱ)若VP﹣ACE
,求证:PD∥平面AEC.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/23e72e83-7552-4255-8d8c-b896597251fd.png?resizew=261)
(Ⅰ)求证:AC⊥PD;
(Ⅱ)若VP﹣ACE
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8fed0174cd8f5b698ea9e04db6b3e45.png)
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【推荐2】如图,在四棱锥
中,底面
为菱形,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2016/6/29/1572844375056384/1572844381347840/STEM/1ad7a94d-ddc1-437e-9569-a63b6cad6738.png?resizew=281)
(1)若
,求证:平面
平面
;
(2)点
在线段
上,
,若平面
平面
,且
,求平面
与平面
夹角的大小.
![](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/b86db010859f7a243badec02946a4e24.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/2016/6/29/1572844375056384/1572844381347840/STEM/1ad7a94d-ddc1-437e-9569-a63b6cad6738.png?resizew=281)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62974d34de3a12418d6b700420afd1b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/845b8505cb7b7b8df5753f52a4e00462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc47768bee81ee0c6fbc41e3fdeb22cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/931bbffda5e872703c9947eccc47ede2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5e9850904cb6d52d2294b7acbedf418.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/487919e07e1b653a14b9e2d53a03a1bc.png)
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