如图,在正方体
中,M,N,G分别是
,
,AD的中点,求证:
![](https://img.xkw.com/dksih/QBM/2015/12/28/1572397608099840/1572397613522944/STEM/7da041e0cc554621874d9737518348f1.png)
(1)MN//平面ABCD;
(2)MN⊥平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8456cee87c4e22351affc28f3a73a0f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a696a182fff038a86b2bbe8ca099442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/554b3b4c5ce7aca81becc07ed4903736.png)
![](https://img.xkw.com/dksih/QBM/2015/12/28/1572397608099840/1572397613522944/STEM/7da041e0cc554621874d9737518348f1.png)
(1)MN//平面ABCD;
(2)MN⊥平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37c8420ec48f9222964ffea8e31fabd0.png)
更新时间:2016-12-03 23:14:02
|
相似题推荐
解答题-证明题
|
适中
(0.64)
【推荐1】已知平行四边形
,
,
,
,
为
的中点,把三角形
沿
折起至
位置,使得
,
是线段
的中点.
![](https://img.xkw.com/dksih/QBM/2016/9/18/1573027213262848/1573027219103744/STEM/371606bd42b049818e31456ad763dab1.png)
(1)求证:
面
;
(2)求证:面
面
;
(3)求四棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e77ea3c01a4f8db68aef920dbee9a64d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657dffbd3623b705f871878fbd9df57e.png)
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![](https://img.xkw.com/dksih/QBM/2016/9/18/1573027213262848/1573027219103744/STEM/371606bd42b049818e31456ad763dab1.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9d32e76582bf550593fdef53e081225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/657dffbd3623b705f871878fbd9df57e.png)
(2)求证:面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83716c0f110a635037adbffc7bbbb183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/483f030abf61c6a0882d656d63cf4512.png)
(3)求四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f91f8a0072c23e917a41e7b172cd547b.png)
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解答题-作图题
|
适中
(0.64)
【推荐2】已知四棱锥
中,底面为矩形,
底面
,
,
,
为
上一点,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2016/11/28/1573185560084480/1573185565655040/STEM/ba30720d16054de7891ef6392333d094.png)
(1)在图中作出平面
与
的交点
,并指出点
所在位置(不要求给出理由);
(2)求平面
将四棱锥
分成上下两部分的体积比.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6153163fecdf3f410411048428ccaef5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/551e4cd76a93de89ea2750160fe74923.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd893c4964b7f1ef69f0563d74c76d0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/2016/11/28/1573185560084480/1573185565655040/STEM/ba30720d16054de7891ef6392333d094.png)
(1)在图中作出平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ddb7c2ca1b6bee86cb24fed02e40da2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ddb7c2ca1b6bee86cb24fed02e40da2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6153163fecdf3f410411048428ccaef5.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.64)
【推荐1】在梯形ABCD中,AD∥BC,BC=2AD,AD=AB=
,AB⊥BC,如图把△ABD沿BD翻折,使得平面ABD⊥平面BCD.
![](https://img.xkw.com/dksih/QBM/2016/1/25/1572464722821120/1572464728989696/STEM/8ec1482a5be64bb0976801ea80321912.png)
(Ⅰ)求证:CD⊥平面ABD;
(Ⅱ)若点M为线段BC中点,求点M到平面ACD的距离.
![](https://img.xkw.com/dksih/QBM/2016/1/25/1572464722821120/1572464728989696/STEM/ed603cd4d8514513a9ce4d9699f3f2fb.png)
![](https://img.xkw.com/dksih/QBM/2016/1/25/1572464722821120/1572464728989696/STEM/8ec1482a5be64bb0976801ea80321912.png)
(Ⅰ)求证:CD⊥平面ABD;
(Ⅱ)若点M为线段BC中点,求点M到平面ACD的距离.
您最近一年使用:0次
解答题-证明题
|
适中
(0.64)
【推荐2】如图所示,在四棱锥
中,
是边长为2的正方形,且
,且
.
![](https://img.xkw.com/dksih/QBM/2017/2/5/1619482427441152/1619482427965440/STEM/e3dccc4a140e4859a6304e9c456f4726.png)
(1)求证:
;
(2)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ce09017ceba47ef27ec67b39e7164b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cf14bc3bfe884ddfff067ba7f410b31.png)
![](https://img.xkw.com/dksih/QBM/2017/2/5/1619482427441152/1619482427965440/STEM/e3dccc4a140e4859a6304e9c456f4726.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac7d8951b216e867fd766ede779d8e4.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
您最近一年使用:0次