名校
解题方法
1 . 将长(
)、宽(
)、高(
)分别为4,3,1的长方体点心盒用彩绳做一个捆扎,有如下两种方案:
方案一:如图(1)传统的十字捆扎;
方案二:如图(2)折线法捆扎,其中
.
![](https://img.xkw.com/dksih/QBM/2021/5/12/2719613202333696/2726629711757312/STEM/592c311b04644a808756ca3cb5e4211c.png?resizew=429)
(1)哪种方案更省彩绳?说明理由:
(2)求平面
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
方案一:如图(1)传统的十字捆扎;
方案二:如图(2)折线法捆扎,其中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c7abfffcc0938732d1c4b2113434607.png)
![](https://img.xkw.com/dksih/QBM/2021/5/12/2719613202333696/2726629711757312/STEM/592c311b04644a808756ca3cb5e4211c.png?resizew=429)
(1)哪种方案更省彩绳?说明理由:
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/156935f303577c3b871cac3a20d82506.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/beea453685213f271ad117e35779b921.png)
您最近一年使用:0次
2021-05-22更新
|
651次组卷
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3卷引用:河北省衡水中学2021届高三下学期三模数学试题