多面体
中,
为等边三角形,
为等腰直角三角形,
平面
,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/6be6fa20-d8cf-48bc-9d86-29a68822ad89.png?resizew=137)
(1)求证:
;
(2)若
,
,求多面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/986ba572d8373df48c996f8c8611498c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c372d059202ec388960b125d4a87dc84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61510c34c5795d7261569b4d09098271.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/810ee7bc82b6f452afb3fc18691abc3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a28d6477c85c5a4ac410a884e92fbe53.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/6be6fa20-d8cf-48bc-9d86-29a68822ad89.png?resizew=137)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38b5c1c5518b9332a2fb209c3621c700.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc1a0e79e49e224c198af0c37405a3ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/beba9c5993784964af81ec070b168456.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/986ba572d8373df48c996f8c8611498c.png)
更新时间:2020-07-08 11:42:20
|
相似题推荐
解答题-问答题
|
较难
(0.4)
名校
【推荐1】在棱长均为
的正三棱柱
中,
为
的中点.过
的截面与棱
,
分别交于点
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/51b01625-bc3d-4e4c-9250-f2007a291167.png?resizew=137)
(1)若
为
的中点,求三棱柱被截面
分成上下两部分的体积比
;
(2)若四棱锥
的体积为
,求截面
与底面
所成二面角的正弦值;
(3)设截面
的面积为
,
面积为
,
面积为
,当点
在棱
上变动时,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/12/51b01625-bc3d-4e4c-9250-f2007a291167.png?resizew=137)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbad16d8800f6d55bd66bd64b1370e4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f737b04ce09bc7e1ed86dc9b3c85203b.png)
(2)若四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd14590987d7987a02d856d427a2da44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e57f00c8225a33458a6b62bff0dcc16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbad16d8800f6d55bd66bd64b1370e4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(3)设截面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0f875de8bec0ffc84b8142f81080058.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54f562eb3c2a45d65cba066d712825a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/646e45a7ffef530bc1d0bd8d4fc72127.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c105d6ba18fbb0581fb982175e2eac9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8010362247509d238c552c670a3429b3.png)
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解题方法
【推荐2】如图所示,已知在四棱柱
中,所有的棱长均为2,侧面
底面
为
的中点,
为棱
上的动点(含端点),过
三点的截面记为平面
.
使得
底面
?请说明理由;
(2)当平面
与平面
所成二面角的余弦值为
时,试求平面
截得四棱柱两部分几何体的体积之比(体积小的部分作比值的分子).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/384ffa4e596b6c7b8e270217a47f7227.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d41a81d84b5bf7bf622431a7a824b53f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f66fb71b75b63594ebeeeebd1963eed5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53e97fcdcfd6183b976a61ef3222c607.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b2556f6e0933a96228609eb1745bf0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fa807136194c18d3ac58902c67f9333.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)当平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff0f4f8e3032f67e672b63791cc4d9df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
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解题方法
【推荐1】在三棱锥
中,
,直线
与平面
所成角为
,直线
与平面
所成角为
.
(1)求三棱锥体积的取值范围;
(2)当直线
与平面
所成角最小时,求二面角
的平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f0ca88506e09b525523845cc336e17e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037fb348109dc2063a268b10eb925a57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1a63ab608517bb10aa036783dfb51f.png)
(1)求三棱锥体积的取值范围;
(2)当直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47d294d69caac577339f11f477b2047e.png)
您最近一年使用:0次
【推荐2】如图所示,在正方体
中,点
在棱
上,且
,点
、
、
分别是棱
、
、
的中点,
为线段
上一点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/6cdf8094-b71d-4477-865e-03ffabb084f5.png?resizew=148)
(1)若平面
交平面
于直线
,求证:
;
(2)若直线
平面
,
①求三棱锥
的表面积;
②试作出平面
与正方体
各个面的交线,并写出作图步骤,保留作图痕迹设平面
与棱
交于点
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fbafedc202bd0d86c4dfdece9f8f4fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f01d1dd10776b00e9df008f03f2608c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87cdc08e1c4a04a18d5ecea03393e36d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/6cdf8094-b71d-4477-865e-03ffabb084f5.png?resizew=148)
(1)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7a447dc58e10adb7c8014071651e7c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b54387f870ae37f7951b253665d64f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ba669c69462fbbff2ef12ea9015fc8.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/565133e91e3ace2b2187cfc6f1db5be6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7a447dc58e10adb7c8014071651e7c9.png)
①求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b03980f99fa0f339388e564466e8b94.png)
②试作出平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbf62b9fe96ad0b0f58c8b3ba3075ab5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbf62b9fe96ad0b0f58c8b3ba3075ab5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394c5d2f55221975503be8aa18022480.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a4a7ba7546acc68f9cff46f1c53557f.png)
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解答题-证明题
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(0.4)
名校
解题方法
【推荐1】如图,在棱长为4的正方体
中,
为
的中点,经过
,
,
三点的平面记为平面
,点
是侧面
内的动点,且
.
,求证:
;
(2)平面
将正方体
分成两部分,求这两部分的体积之比
(其中
);
(3)当
最小时,求三棱锥
的外接球的表面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6795cae2df43a722e1355e9562d93c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7146a372ce6a346fae937622a89d6589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/021a0a080f9ce719709a73a46c3459de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93e0bdfd5676792840d607096ae0555b.png)
(2)平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f737b04ce09bc7e1ed86dc9b3c85203b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1daf42c1a89bda5f17ce22e49dda533.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d0ff310aabd2282b539537ebed3f788.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8049311621004b8d0f2637d13010db7.png)
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解题方法
【推荐2】平面凸六边形
的边长相等,其中
为矩形,
.将
,
分别沿
,
折至
,
,且均在同侧与平面
垂直,连接
,如图所示,E,G分别是
,
的中点.
![](https://img.xkw.com/dksih/QBM/2020/5/31/2474461593632768/2477230549655552/STEM/715a0606-c0d1-4972-9cde-0ccadadaf06b.png?resizew=228)
![](https://img.xkw.com/dksih/QBM/2020/5/31/2474461593632768/2477230549655552/STEM/eccc12c0-0c61-44b9-a28e-09fa4c98c6d5.png?resizew=242)
(1)求证:多面体
为直三棱柱;
(2)求二面角
平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5964426fda51d1e7c8ede53cbfa0d1bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d41c8712cbcbb63b2f8fe556c393b135.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f955e5cc9f108de6f3ca01e5eb84c52e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb944298f2edd73422dea55fd25f0dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99b16cff607cdc2d69afc70dc778acbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://img.xkw.com/dksih/QBM/2020/5/31/2474461593632768/2477230549655552/STEM/715a0606-c0d1-4972-9cde-0ccadadaf06b.png?resizew=228)
![](https://img.xkw.com/dksih/QBM/2020/5/31/2474461593632768/2477230549655552/STEM/eccc12c0-0c61-44b9-a28e-09fa4c98c6d5.png?resizew=242)
(1)求证:多面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7d9dd0666070c144ed761cce26ab076.png)
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【推荐3】如图,在三棱柱
中,四边形
是边长为4的菱形,
,点D为棱AC上动点(不与A,C重合),平面
与棱
交于点E.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/23/d24c04ce-db04-4e92-8d11-2c9457388807.png?resizew=216)
(1)求证:
;
(2)若
,从条件①、条件②、条件③这三个条件中选择两个条件作为已知,求直线AB与平面
所成角的正弦值.条件①:平面
平面
;条件②:
;条件③:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36cf3bff56a7f4ab6c0008e90823025d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/445cfd832967db6bbaa0a2ea311b4f0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0f31a48422525cb066a51b5b6a6673e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a81eb09967a29554c7476e02eae551c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b10b969819d397711310c8dbb399ebc.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/23/d24c04ce-db04-4e92-8d11-2c9457388807.png?resizew=216)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/271bf95761d1cc26b4106214f4166af5.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f085f65b6f426a24b1653dbfec7d70c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c6ca194414a76b40f936e097c504e75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c0b2a4616dbc8c104bbb1cf9ec211d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/445cfd832967db6bbaa0a2ea311b4f0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a4625ece44b3a06dc5968e71e1870e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fc7e2ffe38421dbaf2b7658cafc6dbe.png)
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