如图所示,在边长为a正方体
中,
分别为棱
的中点.
![](https://img.xkw.com/dksih/QBM/2018/10/22/2058996036788224/2061816401215488/STEM/691b0b0cd4a046de9aeded9bef0987e5.png?resizew=246)
(1)求证:点
四点共面;
(2)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42c2d86d8daea5e652d99fe1c6bc3f9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff3147f4dce48df80779e0da83e9d0b3.png)
![](https://img.xkw.com/dksih/QBM/2018/10/22/2058996036788224/2061816401215488/STEM/691b0b0cd4a046de9aeded9bef0987e5.png?resizew=246)
(1)求证:点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42c2d86d8daea5e652d99fe1c6bc3f9a.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8511a1b768df56495af12fc303f869dd.png)
更新时间:2018-10-26 10:39:07
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在四棱锥
中,底面
为菱形,
,
底面
,
,
,
,
分别是
,
,
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/26/372ab7fc-bf36-4f67-a672-4eb05330b1bb.png?resizew=186)
(1)求证:
平面
;
(2)求点
到平面
的距离.
![](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/c6e0b64d25ddd18454f88e40c45d7d8f.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/40d4d36ae30487030b827ce9413b9f13.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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/26/372ab7fc-bf36-4f67-a672-4eb05330b1bb.png?resizew=186)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c27a8fd3bf5b89a16dbbe1a8230653c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐2】如图,五面体ABCDE,四边形ABDE是矩形,△ABC是正三角形,AB=1,AE=2,F是线段BC上一点,直线BC与平面ABD所成角为30°,CE∥平面ADF.
![](https://img.xkw.com/dksih/QBM/2017/12/12/1836956344713216/1861129841508352/STEM/388b97f6-fa36-49f2-90ca-7129c743871f.png?resizew=166)
(1)试确定F的位置;
(2)求三棱锥A-CDF的体积.
![](https://img.xkw.com/dksih/QBM/2017/12/12/1836956344713216/1861129841508352/STEM/388b97f6-fa36-49f2-90ca-7129c743871f.png?resizew=166)
(1)试确定F的位置;
(2)求三棱锥A-CDF的体积.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,已知平面
∩平面
=AB,PQ⊥
于Q,PC⊥
于C,CD⊥
于D.
![](https://img.xkw.com/dksih/QBM/2012/2/7/1570719944933376/1570719950356480/STEM/bc4b3ca615e34257a2e757ff2cd86cc1.png?resizew=127)
(1)求证:P、C、D、Q四点共面;
(2)求证:QD⊥AB.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://img.xkw.com/dksih/QBM/2012/2/7/1570719944933376/1570719950356480/STEM/bc4b3ca615e34257a2e757ff2cd86cc1.png?resizew=127)
(1)求证:P、C、D、Q四点共面;
(2)求证:QD⊥AB.
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,点
在平面
外,△
在平面
内,
、
、
、
分别是线段
、
、
、
的中点.
![](https://img.xkw.com/dksih/QBM/2019/12/31/2373622799450112/2409427470417920/STEM/6dc69e051dfd4b738b9809fb81b196ce.png?resizew=169)
(1)求证:
、
、
、
四点在同一平面上;
(2)若
,
,异面直线
与
所成角为60°,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://img.xkw.com/dksih/QBM/2019/12/31/2373622799450112/2409427470417920/STEM/6dc69e051dfd4b738b9809fb81b196ce.png?resizew=169)
(1)求证:
![](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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1682d306c38087d9e6f7efb9cec596a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d71e6ea7333dbc78d0a7b9bc3892f940.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/31e55e398e8520d8a36fb5a625a085b8.png)
您最近一年使用:0次