如图,在多面体
中,
平面
,平面
平面BCD,其中
是边长为2的正三角形,
是以
为直角的等腰三角形.
(1)证明:
平面
;
(2)若平面
与平面
的夹角的余弦值为
,求线段
的长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6168500f2a20194f7b657abd98518f75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2b265d121f9ebc13671a5719604476a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661ff55b5ebbadfb600989af3cfce2fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a72dfbf0138a611174c36ce077e0c47.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/25/74186e9c-de64-4aeb-8d8d-343fb9657e16.png?resizew=149)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68fdb2b9d6a4a54ed1328c5b3adcf7b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a8991a565ddba90f56521473bd7f374.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
更新时间:2023-09-25 16:06:36
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,在多面体
中,四边形
是菱形,
相交于点
,
,
,平面
平面
,
,点
为
的中点.
![](https://img.xkw.com/dksih/QBM/2020/7/9/2502375922548736/2502422162808832/STEM/e1a3898f40f7496182d38eb7b58d8ee0.png?resizew=301)
(1)求证:直线
平面
;
(2)求证:直线
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3c032441543354c154ee67d744abb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e41d3f7d55fcbaebc4e2450ac63a3dc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed6034301fc4110da89bdb0f46ad82ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd2d28f1e7a6b17401c19c34beddcbe0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cf5b86308e9f777a6611503ba8d0e9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/2020/7/9/2502375922548736/2502422162808832/STEM/e1a3898f40f7496182d38eb7b58d8ee0.png?resizew=301)
(1)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/684a04f6d996bf66c45b5160111dcf43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e41c2d7ae6aaf6d91129ed5221a415a7.png)
(2)求证:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/820567942aa98b2feaaa017fcb7790df.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图所示,正方形
与矩形
所在平面互相垂直,
,点
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/9cf13e68-fad6-4bbf-a4fb-c6cad069e1c3.png?resizew=251)
(1)求证:
平面
;
(2)设在线段
上存在点
,使二面角
的大小为
,求此时
的长及点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7253ffd3fc633d861810ee2e872188b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f80f51c31583fea58fde645474d60b8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/9cf13e68-fad6-4bbf-a4fb-c6cad069e1c3.png?resizew=251)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f11f1840eb8b17e7b07c3fe7e987a9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657dffbd3623b705f871878fbd9df57e.png)
(2)设在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d46c158824d9d1cc8eb3bcddbecbec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c67d01e61dc0042e67b5e8ec8e727c22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/347edae89c2a0a9785252a624a2c0960.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐3】如图,在四面体ABCD中,
平面BCD,
,
,M是AD的中点,P是BM的中点,点Q在线段AC上,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/30/1c0d631a-61d4-4db4-a720-4f645e610e0f.png?resizew=170)
(1)求证:
平面BCD;
(2)求PQ与平面BCM所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee0f630195bcf6c3ca8f4fdeff43b082.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a20cb14fea4a7cad4b7775a3dd67df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/276e3c9755dbd39fb01de614840d230f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/30/1c0d631a-61d4-4db4-a720-4f645e610e0f.png?resizew=170)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c203fa3cafdc1d924b61ee1d83a3ecf3.png)
(2)求PQ与平面BCM所成角的正弦值.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,三棱台
的底面是正三角形,平面
平面
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/d6ecc35a-01f5-49c0-af47-8cc97310d40c.png?resizew=165)
(Ⅰ)求证:
;
(Ⅱ)若
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45378fbdfb5fe305c71893a91435854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/616b46476c1f1d22e3a21d6fa33a3400.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a2a38637b1e598516dc7823831a62b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/19/d6ecc35a-01f5-49c0-af47-8cc97310d40c.png?resizew=165)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc0666d63e6c13fa6a19b59523aa1eb.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e693fd6ced67fe9f21892eda2034a8a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aedb55703d202771dd11987cf4f30bf6.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,已知四棱锥
中,四边形
中,
,
,
,
,直线
在平面
内的投影恰好是
中
边的中线
,且
.
![](https://img.xkw.com/dksih/QBM/2021/12/17/2874604194136064/2912215055917056/STEM/fcf54446-f9ee-406b-b97e-5c8fd1b33b07.png?resizew=151)
(1)求证:平面
平面
;
(2)若
为
上一点,满足
,求平面
与平面
所成锐二面角余弦值.
![](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/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23e571f73279a90a85c0689166f1adef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/177678001b2ccde1db8f57fa5e017002.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db27b7f29d7d01b2692f217bc3079fc4.png)
![](https://img.xkw.com/dksih/QBM/2021/12/17/2874604194136064/2912215055917056/STEM/fcf54446-f9ee-406b-b97e-5c8fd1b33b07.png?resizew=151)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d44e9d90906ca4539184769b3003fd28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22ce50ba5e349425274f05d46d120a74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】在如图所示的七面体
中,底面
为正方形,
平面
.已知
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/1/dcbe7f97-4f1d-4a6b-9c0f-b56093efeba7.png?resizew=220)
(1)设平面
平面
,证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
平面
;
(2)若平面
平面
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/806625a93511075586360d7f9f335f7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a488b8a4c49543c3c92d32cd3afe8f43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83d7df6a7ae34a3d3504b0ef41ceb53a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/1/dcbe7f97-4f1d-4a6b-9c0f-b56093efeba7.png?resizew=220)
(1)设平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac0ee6608ab3ae63b54cd3330d30b6d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca30bfcdc238350c0b1495a3e012e7a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b750987c52800d1d5c0ff50f82cc643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b896abbe80bff63a275ef2e1550c2de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图,在四棱锥
中,底面
是菱形,
与
交于点
,平面
平面
为线段
上的一点.
(1)证明:
平面
;
(2)若二面角
余弦值为
,求
的值.
![](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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc3891e78d0500033bdf60e825adaf92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4295261db84831c4eb7a4ea71e33c7c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/1/167b1311-4ebb-48cd-a1f3-f8ac23c4a30b.png?resizew=200)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324a1792318a3528772781fac2b4d2e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfe6feea0d50194a3d156da6f49a9d0c.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐3】在三棱锥
中,
,平面
平面ABC,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/22/24b554a3-f871-428d-9d93-7172b0969ec4.png?resizew=147)
(1)证明:
平面
;
(2)棱BC上是否存在点D,使得面
与面
的夹角为
?若存在,求BD长度;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a15a004f7d47ed595f063e60075223a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db99494753dbb4588ded0394a9e18607.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/376c005548874df605a76a086a82c76c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a9b8e7befcb7881c294070175b1a554.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/22/24b554a3-f871-428d-9d93-7172b0969ec4.png?resizew=147)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4da035673ef0edcfae6b72fb5e5ba34a.png)
(2)棱BC上是否存在点D,使得面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27d39f37441ee55dbc8f1a6ca199a66b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3520ee9cc97a075e889e1625dba1157c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c8ae071199874d9d74a4919a58902f7.png)
您最近一年使用:0次