《九章算术》是我国古代数学名著,它在几何学中的研究比西方早1000多年,在《九章算术》中,将底面为直角三角形,且侧棱垂直于底面的三棱柱称为堑堵(qian du):阳马指底面为矩形,一侧棱垂直于底面的四棱锥,鳖臑(bie nao)指四个面均为直角三角形的四面体.如图在堑堵
中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/1c29406e-4c8f-4ce3-bbfd-04e55081c1ce.png?resizew=139)
(1)求证:四棱锥
为阳马;
(2)若
,
,且直线
与平面
所成角的正切值为
,求锐二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/1c29406e-4c8f-4ce3-bbfd-04e55081c1ce.png?resizew=139)
(1)求证:四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29a0c82028e1259f300facd32775a15e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39b304c67046ab1b716b6c072f8ba898.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24bb49fdc6b6bbb2449fdf8a0de769d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2ead078d0c9a22439c512767bf3d4c7.png)
更新时间:2020-12-12 22:36:14
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相似题推荐
【推荐1】如图(1),在平面五边形
中,
,
,将
沿
折起得到四棱锥
,如图(2),
是棱
上一点,且
,连接
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/20/c8c01800-0d0c-4e99-b2ce-95effd7e0cfd.png?resizew=292)
(1)求证:平面
平面
;
(2)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea1e3a43d0fa18f6c0888ba804d5b329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c1e4ee4b547fb9aeb0eed00dfba3129.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c1a52af1d73eaf70fb7302a20b5419.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ada8229d7ff59587301f55fa5310255.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa934dccd11401e8872835f36e65396.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2626a034d2894bd70aa5136f87c7774b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/20/c8c01800-0d0c-4e99-b2ce-95effd7e0cfd.png?resizew=292)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a26a7784c7419d8359fb119c8ecc03d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9068f29d671d76d1e95ba3a4eaff5b96.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,四棱锥
中,
底面
,底面
为矩形,
,
,M,N分别为PB,CD的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/15/2ba2b052-9cf6-4f90-9e6c-b2840bb7ccea.png?resizew=196)
(1)求证:
面
;
(2)求直线PB与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b388f9915195687e417e2ffc4a55a311.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/15/2ba2b052-9cf6-4f90-9e6c-b2840bb7ccea.png?resizew=196)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93cf663ee2bf1ac5c43f4306fa0cf250.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
(2)求直线PB与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1885efcff0b903e314057dd153578600.png)
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】在如图所示的几何体中,四边形
是边长为2的菱形,
平面
,
,
.
![](https://img.xkw.com/dksih/QBM/2011/4/16/1570120827936768/1570120833286144/STEM/260a87878bb54a3ab256471194ae7d76.png?resizew=213)
(1)证明:平面
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d2d217e9bcd059908f117dfc4d4259.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daee8baa62b5b8d5db41eab0d360ee51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90d2cf3f3b69507a66a9236f62ee2c5e.png)
![](https://img.xkw.com/dksih/QBM/2011/4/16/1570120827936768/1570120833286144/STEM/260a87878bb54a3ab256471194ae7d76.png?resizew=213)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42ce82a4c37365f2d4dea2c4ad2e3288.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f84f169e50dc59d4f7a8e1e36f5c847.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89c9c2c831a0552a7c934365bc49ad3f.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】已知在几何体中,四边形
是边长为
的正方形,且
平面
,
,且
,
与平面
所成角的正切值为
.
![](https://img.xkw.com/dksih/QBM/2018/4/21/1929116377399296/1932980799062016/STEM/56a24babfa4346e585c8789f312b443d.png?resizew=139)
(1)求证:平面
平面
;
(2)求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.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/95025408f605d8e69eac05e2a23bb45e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c83e24fa587c15a97b695787024cab17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/821309f088a175c00dc0f4828334503d.png)
![](https://img.xkw.com/dksih/QBM/2018/4/21/1929116377399296/1932980799062016/STEM/56a24babfa4346e585c8789f312b443d.png?resizew=139)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d2ed7474932ac3959108f2b835acf98.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐3】如图所示,在四棱柱
中,四边形ABCD为矩形,
,四边形
为菱形,
,平面
平面ABCD,点E为线段AB的中点,M为线段AE的中点.
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963830207176704/2968870012092416/STEM/068f813d-383b-4c7d-8298-61f4df85d399.png?resizew=225)
(1)证明:
;
(2)求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7feafad81941cce281988e9e53155ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e22ebcc4aa98d46366df48f751a5f368.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86b8f000e876a46d2a0cb4295bea780c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f67c2d29909f744a60448e409f0fbab.png)
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963830207176704/2968870012092416/STEM/068f813d-383b-4c7d-8298-61f4df85d399.png?resizew=225)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/847b003fe0a6c20c6eeded225c3d950f.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45d365ce9f4bacc4d4bb15dbdb5306a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/475d9dbaac17f65044500bd8fad9a135.png)
您最近一年使用:0次