1 .
的内角
,
,
所对的边分别为
,
,
.已知
,
,且
.
(1)求
;
(2)证明:
的三个内角中必有一个角是另一个角的两倍.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.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/be665daedefcac6f6a95c360261f4753.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2563eddff2d780d854cc7f777283556c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47731780c0362fe19b0aae6654d57c96.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
您最近一年使用:0次
2018-03-29更新
|
575次组卷
|
3卷引用:河南省新乡市2018届高三第二次模拟测试数学(文)试题
2 . 如图,已知
是
中
的角平分线,交
边于点
.
![](https://img.xkw.com/dksih/QBM/2018/2/12/1880868863131648/1882648412651520/STEM/ca5109a6a19f429d8cb8e4332439e12f.png?resizew=234)
(1)用正弦定理证明:
;
(2)若
,
,
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://img.xkw.com/dksih/QBM/2018/2/12/1880868863131648/1882648412651520/STEM/ca5109a6a19f429d8cb8e4332439e12f.png?resizew=234)
(1)用正弦定理证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea5ca418ff0d36929cd06551f74d58c2.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fffa3d9c32da53b0ea0c338012ea20c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca036d049f5205cf04cb1b9c5cd03f97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
您最近一年使用:0次
2017-12-15更新
|
1059次组卷
|
9卷引用:【全国百强校】河南省信阳高级中学2019届高三上学期期末考试数学(文)试题
【全国百强校】河南省信阳高级中学2019届高三上学期期末考试数学(文)试题河南省濮阳市南乐县第一高级中学2022-2023学年高三上学期10月月考文科数学试题内蒙古呼和浩特市2018届高三11月质量普查考试数学(理)试题内蒙古呼和浩特市2018届高三年级质量普查调研考试数学理试题湖北省荆州中学、宜昌一中等“荆、荆、襄、宜四地七校考试联盟”2018届高三2月联考数学(理)试题2【全国百强校】湖南省衡阳市第八中学2019届高三上学期第二次月考数学(理)试题【全国百强校】湖南省衡阳市第八中学2019届高三上学期第二次月考数学(理科)试题山西省长治市第二中学2022届高三上学期第三次练考数学(文)试题黑龙江省牡丹江市第一高级中学2022-2023学年高三上学期期中考试数学试题
解题方法
3 .
的内角
的对边分别为
,其中
,且
,延长线段
到点
,使得
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/14/07ccb9fd-ad8a-43aa-a0d1-06c504c771fd.png?resizew=223)
(1)求证:
是直角;
(2)求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad5e009486af263893ca8290be72f258.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e762fe2dd40d314915682433b2af063.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/621eac61060a4a74c70142896d1f8736.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/14/07ccb9fd-ad8a-43aa-a0d1-06c504c771fd.png?resizew=223)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae42e850ec491355a9f5e73676c02e5e.png)
您最近一年使用:0次
2017-05-22更新
|
680次组卷
|
3卷引用:河南省豫南九校17-18学年高二上学期期末联考理科数学试题
真题
名校
4 . 在△ABC中,角A,B,C的对边分别为a,b,c.已知,
.
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2eb5a1b9b54e852529508bcc1b418752.png)
(2)若
,求△ABC的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/033d3b68d34fb909ca6e6be21fa751e1.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2eb5a1b9b54e852529508bcc1b418752.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea6f68598041c41726e8c4e411243180.png)
您最近一年使用:0次
2016-12-01更新
|
3147次组卷
|
6卷引用:河南省信阳高级中学2021-2022学年高二下学期4月月考数学(文)试题
5 . 选修4-1:几何证明选讲
如图,
是圆
的直径,
∥
,点
在
上,
分别交圆
于点
.设圆
的半径为
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/13/7b63f0a2-c517-4efa-886f-c006b7112aca.png?resizew=141)
(1)证明:
;
(2)若
,求
的值.
如图,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/154db565152fbc5b17bb428810df6bb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39acab3cfb59bfc9591371721ab01d93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1106b5ca0fadc19d025a6bb68afe0431.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/13/7b63f0a2-c517-4efa-886f-c006b7112aca.png?resizew=141)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cc245e6993083d4c93ca3c856f4d1b5.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32a13487bb9e0f3774fd13d8df15836b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc267b693f0f921f2a34805126dd3ba0.png)
您最近一年使用:0次
2016-12-04更新
|
213次组卷
|
3卷引用:2017届河南开封市高三上10月月考数学(理)试卷
解题方法
6 . 在
中,
的对边分别为
,且
.
(1)证明:
;
(2)若
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6db9829a71d5bd47e098e9a211a4179a.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0674ffde4647ba503efafd67fbe11f4.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5951d6753001779e8005133072e993da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次
解题方法
7 . 在
中,角
的对边分别为
,且
(1)证明:
是钝角三角形;
(2)若
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d30a6b906c218e9331293d54d772eeb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e4a14bb9a194eebc8d8101929fa74b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
您最近一年使用:0次