如图所示,在四棱锥
中,平面
平面
,
,
是等边三角形,已知
,
.
![](https://img.xkw.com/dksih/QBM/2020/6/8/2480336113901568/2480765800988672/STEM/50eec9a140784640942736cc5710038f.png?resizew=175)
(1)设
是
上的一点,求证:平面
平面
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a4426db778693c875e2dca9220875d9.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/fcd8e727e4efc22b49649f71ae9c9d84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58579094b5d753e9205c2ec89ca3ae07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5e8d9bd81b063a824baf17d947db5ee.png)
![](https://img.xkw.com/dksih/QBM/2020/6/8/2480336113901568/2480765800988672/STEM/50eec9a140784640942736cc5710038f.png?resizew=175)
(1)设
![](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/a6fb16d2f0db758b8b7a8d3743143f48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b172e3aae625013716b30fae2c59279.png)
更新时间:2020-06-09 08:33:51
|
相似题推荐
解答题-证明题
|
较易
(0.85)
名校
解题方法
【推荐1】如图,在正方体
中,E是
的中点.
平面ACE;
(2)若
,求三棱锥B—AEC的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0424446817f60c18f8e4e3cc202ad99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb96d9ea39bf7974143973559058dbec.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0387c9dd6759a28c8beceef04f8a5a62.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
解题方法
【推荐2】直三棱柱
中,
为正方形,
,
,M为棱
上任意一点,点D、E分别为AC、CM的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/8/53ef0522-8a05-438d-90ad-7c82c2c8030c.png?resizew=181)
(1)求证:
平面
;
(2)当点M为
中点时,求三棱锥
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/7e918b70b02a73685e3c536c7f380e2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/8/53ef0522-8a05-438d-90ad-7c82c2c8030c.png?resizew=181)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75aea24647cd4d0b4b9aa513bf5457b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9edc50f7febbc2d5d8dcdc23a3630a7.png)
(2)当点M为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4711ea198eebe0a72ef2c66a9dd51b83.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
【推荐3】在如图所示的多面体AFDCBE中,
平面BCE,
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/8e50ecd8-0f90-49a0-b56f-de6dafdea29c.png?resizew=130)
(1)在线段BC上是否存在一点G,使得
平面AFC?如果存在,请指出G点位置并证明;如果不存在,请说明理由;
(2)当三棱锥
的体积为8时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9518d0a9119d9416b5198086dd724dfb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4fb90434b6da93bdc6590f769ef118b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeedb5f361a1baff6338436fff6c471d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60c75db43b9f0ac678fdc00372eb763a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/8e50ecd8-0f90-49a0-b56f-de6dafdea29c.png?resizew=130)
(1)在线段BC上是否存在一点G,使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b8badfeb9e7556486e02ab60df4dd32.png)
(2)当三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27e024a87e5b48bfa241169def613104.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5680c88274fe3de009b76721b1128e0d.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
解题方法
【推荐1】在四棱锥S﹣ABCD中,底面ABCD是菱形,△SBC,△SDC为正三角形,E为侧棱SC上一点.
![](https://img.xkw.com/dksih/QBM/2021/2/8/2653449665716224/2658588328214528/STEM/843e0f37-d497-4f9a-997f-0f957f4e69a8.png)
(1)当E为侧棱SC的中点时,求证:
平面BDE;
(2)求证:平面BDE⊥平面SAC.
![](https://img.xkw.com/dksih/QBM/2021/2/8/2653449665716224/2658588328214528/STEM/843e0f37-d497-4f9a-997f-0f957f4e69a8.png)
(1)当E为侧棱SC的中点时,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1ea0adc03fc8ba355dbdac586f4b707.png)
(2)求证:平面BDE⊥平面SAC.
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
【推荐2】如图,在四棱锥
中,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81ae3533891b5c82760853e4ba06dfc9.png)
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/354ead90-4427-450b-b559-85afb45753c0.png?resizew=178)
(1)求证:平面
平面
;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81ae3533891b5c82760853e4ba06dfc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38c8b54beba73d15e31fb66c2e3b1128.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/354ead90-4427-450b-b559-85afb45753c0.png?resizew=178)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99e77e93fb69b4c0716dde86f52e7406.png)
您最近一年使用:0次