在△ABC中,角A,B,C所对的边分别a,b,c.下述三个条件:①
;②
;③
.选其中一个条件完成下列问题
(1)求A;
(2)若
,△ABC的面积为
,求△ABC的周长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/beba6a56679532601e9ab856369af2b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ad3fad448d5084d40479a6e8c96549.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84e9331a0aeb6be20548b99981a93c75.png)
(1)求A;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/783d6adfa8fb1352679c5185258d842a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edb57d84f9bbcb3e30d4ce7e2e1e8604.png)
更新时间:2021-10-10 10:23:32
|
相似题推荐
【推荐1】在①
,②
,③
中选一个,补充在下面的横线中,并解答.
在
中,内角A,B,C的对边分别为a,b,c,且满足________.
(1)求A;
(2)若内角A的角平分线交BC于
点,且
,求
的面积的最小值.(注:如果选择多个条件分别解答,那么按第一个解答计分)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de85c2f2913e63559917a3fb1c0a7ba5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee63b3e059cb9f5848eb6c893a5bd8c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d4805200a51051848f9e30d05199ae4.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(1)求A;
(2)若内角A的角平分线交BC于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d783fe7f3ce673d5d21281174e7a7968.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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适中
(0.65)
【推荐2】已知向量
且与向量
所成角为
,其中
的内角.
(1)求角
的大小; (2)求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ae13d419273c5224662d183f9de535b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6b1e0d8ca4d790221398659e01cc2e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d88591679796c52024d11c4de641bdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/caeb9d3623e4ad3a8f6a9322700eb365.png)
(1)求角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0577566dbcc526fb6f783491a4784902.png)
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适中
(0.65)
名校
解题方法
【推荐1】在①
,②
,③
这三个条件中任选一个,补充在下面的横线上,并加以解答.
已知△ABC的内角A,B,C所对的边分别是a,b,c,若____________.
(1)求角B;
(2)若
,求△ABC周长的最小值,并求出此时△ABC的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f1d5b50db0b87df7a8907a4e0699b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6df2aa5ec7101c7dd355f0cab6f4fe31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70162c05e236f881578f2c6e9507b6b4.png)
已知△ABC的内角A,B,C所对的边分别是a,b,c,若____________.
(1)求角B;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9be4380bdcef1c542604a6ad61642c0f.png)
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【推荐2】在
中,角A,
,
的对边分别为
,
,
,已知
.
(1)求角A的大小;
(2)若
,
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d83af3cb48e95e21e63472ae4a5ab667.png)
(1)求角A的大小;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33234f1f9c65ad02a59b9c007d59ef41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2671f3e6bb4374578bcd5d35fb358840.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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适中
(0.65)
解题方法
【推荐1】如图,在矩形ABCD中,
,
,E为边AD上的动点,将
沿CE折起,记折起后D的位置为P,且P在平面ABCD上的射影O恰好落在折线CE上.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/29/28a83479-0643-4ba2-92bf-6659d77b4413.png?resizew=477)
(1)设
,当
为何值时,
的面积最小?
(2)当
的面积最小时,在线段BC上是否存在一点F,使平面
平面POF,若存在求出BF的长,若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a0acc93490a6a784eb62201d93dd93d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/29/28a83479-0643-4ba2-92bf-6659d77b4413.png?resizew=477)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b9cd3d8e6059030fb2cbfb62c791faa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c025ee3317be1099b7bf03a11e37ed4.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c025ee3317be1099b7bf03a11e37ed4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e92c3dbf9981a81f4093c9760943e21c.png)
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|
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(0.65)
名校
【推荐2】已知△ABC的内角A,B,C所对的边分别为a,b,c,向量
,且
.
(1)求A;
(2)若
,求△ABC的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f02663c5db24c7e2f059565247211140.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/401078c16ea92130b47f728bea699c62.png)
(1)求A;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a53437e83aa2647e9bcc979db88c1453.png)
您最近一年使用:0次