如图,在三棱柱
中,侧面
底面
,
,且点O为
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/23516e39-6b8b-4c3a-9bf9-69cb97703489.png?resizew=223)
(1)证明:
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/966570e5df2706ade643c09a3018350b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/23516e39-6b8b-4c3a-9bf9-69cb97703489.png?resizew=223)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5021c7ed2dcd938d00723032b1d71e.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/861d61d2b7b16e12fd97f870fb3fa522.png)
更新时间:2020-07-15 07:10:07
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相似题推荐
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解题方法
【推荐1】如图已知四棱锥A-BCC1B1底面为矩形,侧面ABC为等边三角形,且矩形BCC1B1与三角形ABC所在的平面互相垂直,BC=4,BB1=2,D为AC的中点.
![](https://img.xkw.com/dksih/QBM/2020/7/21/2510816558587904/2511607229235201/STEM/ef886d8b5b1542509e1dd8c0af546681.png?resizew=124)
(1)求证:
平面
;
(2)求点D到平面ABC1的距离.
![](https://img.xkw.com/dksih/QBM/2020/7/21/2510816558587904/2511607229235201/STEM/ef886d8b5b1542509e1dd8c0af546681.png?resizew=124)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1c920d02068d0e63ffdab70786c526d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4294ffdba16ae69fd03b13959d682aba.png)
(2)求点D到平面ABC1的距离.
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【推荐2】如图,四棱锥
中,平面
平面
,
,
,
,
,
为线段
上一点,
,
是线段
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/9cb7717f-33d1-4117-94c2-3d866e0f14e0.png?resizew=189)
(1)证明:
平面
;
(2)若
,求四面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a49f6992e79c285b9f82e49a74d2fc5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0f53e52dafe4cbe638fbbe183c4c54b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b83cb6327dcbc8a998e6586bcfa7a3b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d65bb0407b1f1d74d6696be742d0aa05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/9cb7717f-33d1-4117-94c2-3d866e0f14e0.png?resizew=189)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b503c5da1208576c9fabd3685153c9d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8db2bec6ebe672e8f83f24e9bdf4654.png)
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【推荐1】在如图所示的多面体中,
且
,
,
,且
,
,且
,
平面
,
.
![](https://img.xkw.com/dksih/QBM/2021/11/5/2844656972963840/2848553311805440/STEM/d9954a0d33b44070b4fd77849f7a5621.png?resizew=211)
(1)求证:
;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e839ac941e8bf536ff35a12e56c7a400.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1989dc6aef61c294690d2105c72e894a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66514e4d9ad91dbc0cc4330de68a29e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddb8a11edd393eafd58d9b886dbc7a2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ae554534d93527d59e71ec6bd2a630b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3cf187bc2ede965870b90757b495f53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81b091ee5a8b32424b2b836dde7860c7.png)
![](https://img.xkw.com/dksih/QBM/2021/11/5/2844656972963840/2848553311805440/STEM/d9954a0d33b44070b4fd77849f7a5621.png?resizew=211)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5962e313ee2fc020c2e08b63ce9c17a5.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926584088b939200d88e64318f2d4e6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6541c0cb89f08aa4c937c0beb915e0a7.png)
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【推荐2】如图,四棱锥
的底面为矩形,
平面
,
为
的中点,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/58cdc4a1-85d6-4e9b-bca2-d779539ee126.png?resizew=153)
(1)证明:平面
平面
;
(2)若
,求该四棱锥的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.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/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/186e5e7efe51fd25b9e38dc0fa23de9d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/58cdc4a1-85d6-4e9b-bca2-d779539ee126.png?resizew=153)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/392469b357b12b998528499929366c02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10ca5b5fd1031438de2d2dd59be8c348.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb00ae02bd12addc5f71f609658fc549.png)
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【推荐3】在四棱锥
中,底面为矩形,
,面
面
为
的中点.
(1)求证:
;
(2)当
与面
所成的角为45°时,求
与面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a11113194fb826268712d14254837724.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23d11e19c84255eb0431415c2dec553d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/26/3141195e-9f9b-449c-b004-0e2a13f495fd.png?resizew=194)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d5ee2d6fcbcad17b69997ef0741d2d.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bf12905647aeeded72bbca21a63f319.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
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【推荐1】如图1,在边长为2的菱形
中,
,点
分别是边
上的点,且
,
.沿
将
翻折到
的位置,连接
,得到如图2所示的五棱锥
.
平面
?证明你的结论;
(2)若平面
平面
,记
,
,试探究:随着
值的变化,二面角
的大小是否改变?如果改变,请说明理由;如果不改变,请求出二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea4f5eec0addba78f2e0cdfb7ecc59a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/481e426224c3a3ce9bb5a731eed81c40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07d7a3d7f32ce2b4baa1f9346dc7e3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3e06b8bc2571146b241e6028a742e3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12225a1a1eda07908309f8100cc34726.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ed4c4e8edbd179f3fc38a6653f18c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b99271fe84300da304205280de1b63e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43d865d5674e5c4e15946e45dce8dc2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c4180c271831327644dc83240b715b5.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9ab73fd4ddacc0c1524f8d742c7dcd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e470e983b075e6442750758e11081e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f342c5e045dba220e9c37b0bb769e4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eb6bf23a5a12e1ba5413594d7b1a57c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd6e39e62dad9881e30ac929c1f2958e.png)
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【推荐2】如图,已知在三棱柱
中,平面
平面
,且平面
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/25/a221d757-b6c7-4110-b295-9b07ed8b0cb8.png?resizew=151)
(1)证明:
平面
;
(2)若
,
,
,
分别为
,
的中点,
,
,求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71f2185273bf04c11118c7954f7ec822.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84f4d9c3f1e496cc3fa3401ffaedd7e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdcfe69b939fd1c271747fe9d37ccdf9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/25/a221d757-b6c7-4110-b295-9b07ed8b0cb8.png?resizew=151)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d97e150793ad48c641db0cc74aaa341.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e4f0c1c9cca0555906d8a53e1a6803d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657d5471e57b894c3833bb3f43ff38ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ea0df817e3e2cd95b9cd8f73386834c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24cfad1ba71a78d8f415335cde2f8c52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb0628cecbfc98d390e5447d52414e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dcb4ac0912b7d7a1dbf6107d30a41f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f1fc5de1aa6c80c8bbb390adc620543.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1885efcff0b903e314057dd153578600.png)
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【推荐3】如图,已知四棱锥![](https://staticzujuan.xkw.com/quesimg/Upload/formula/362a28fb4dc71e5c5c747476089b1f37.png)
是边长为4的等边三角形,满足
,
.
(1)求证:
;
(2)若
与平面
所成的角为
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/362a28fb4dc71e5c5c747476089b1f37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0041488020a3e19377b18a70fbf82e7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c915947abe543935611182f40d5827f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/10/42f6b89e-396e-4f98-b65c-b29a0542a38d.png?resizew=192)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/352d85caf2bd9c6c66709d09df0ee0ac.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15615de1a6df206dbd081251f676578e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1636b4530c0b42d0e0b649e90e3b9e85.png)
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