解题方法
1 . 古希腊数学家海伦的著作《测地术》中记载了著名的海伦公式,即利用三角形的三边长求三角形面积.若三角形的三边分别为a,b,c,则其面积
,其中
.
(1)证明:海伦公式;
(2)若
,
,求此三角形面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c667f76da3658f200fff8eadb24b8e82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0f2d50ca5cc415bf6721faf2221d626.png)
(1)证明:海伦公式;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36e15cbd7c42d7b15d7ba8d2b28ab8df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94d7e2c43c8d5612f6bc2a248f42b659.png)
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2022·全国·模拟预测
解题方法
2 . 在①
,②
,③
且
这三个条件中任选一个,补充在下面问题中,并解答.
在△ABC中,内角A,B,C的对边分别为a,b,c,______.
(1)求证:△ABC是等腰三角形;
(2)若D为边BC的中点,且
,求△ABC周长的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/981cb688a4e15d31e7a43115aa701f98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa6ae5122d84253a8f5b87da2e389603.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e2e6dd48b13e0c4dcd7f0eaf474f36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a68c4981b1a17cee55c5088c092af9d5.png)
在△ABC中,内角A,B,C的对边分别为a,b,c,______.
(1)求证:△ABC是等腰三角形;
(2)若D为边BC的中点,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4aca5534bce25acaeb7379deed8f8f.png)
您最近一年使用:0次
名校
解题方法
3 . 在
中,设内角
,
,
所对的边分别为
,
,
.若
.
(1)证明:
;
(2)若
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/72c573728c6d5c61cb02dea29b03db1c.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f43e603c47efbbcb8570bd9a4891b679.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29fba806556be445adb6fa65774ed091.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5201fc26d013f6fb889933c0e32f5c53.png)
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2023-07-08更新
|
235次组卷
|
2卷引用:广东省肇庆市2022-2023学年高一下学期期末数学试题
名校
解题方法
4 . 古希腊的数学家海伦在其著作《测地术》中给出了由三角形的三边长a,b,c计算三角形面积的公式:
,这个公式常称为海伦公式.其中,
.我国南宋著名数学家秦九韶在《数书九章》中给出了由三角形的三边长a,b,c计算三角形面积的公式:
,这个公式常称为“三斜求积”公式.
(1)利用以上信息,证明三角形的面积公式
;
(2)在
中,
,
,求
面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/684c13a2cea962fb204256ca433a4d58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a822dd4e1d3859f55874669092697a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96bd5fefb9a7c618d1ef8d73b3c43cd4.png)
(1)利用以上信息,证明三角形的面积公式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/634fdb49ecc32befaf9ac4ce84ae5a37.png)
(2)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49dcdf048e907e670072f1070c8a8b6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3696bff45e67a5a0cbd0ca5b253e3e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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2023-07-06更新
|
1041次组卷
|
4卷引用:广东省广州市白云区2022-2023学年高一下学期期末数学试题
广东省广州市白云区2022-2023学年高一下学期期末数学试题浙江省2023-2024学年高一下学期3月四校联考数学试题河南省信阳市新县高级中学2024届高三4月适应性考试数学试题(已下线)专题02 第六章 解三角形及其应用-期末考点大串讲(人教A版2019必修第二册)
名校
解题方法
5 . 在
中,角
、
、
的对边分别为
、
、
,且
.
(1)求
的最大值;
(2)求证:在线段
上恒存在点
,使得
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/86377ffad61925cd77ab4ed493e94c85.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca69890d870ac9a79fe891ff57396e37.png)
(2)求证:在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b2cd303cd194c700b1a9d048d23662f.png)
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名校
解题方法
6 . 已知锐角三角形
中,角
的对边分别为
,且满足
.
(1)求证:
;
(2)若
,求三角形
面积的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.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/f68692f3c3b550f985620cef8212a36a.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f44c181a2f6ae22d5d52b374768dc57.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e258ab9e600435b37465092243d99f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
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2023-03-28更新
|
810次组卷
|
2卷引用:四川省内江市第六中学2022-2023学年高三下学期第一次月考理科数学试题
解题方法
7 . 任意三角形射影定理又称“第一余弦定理”,即:在
中,A,B,C的对边分别是a,b,c,则
,
,
.
(1)用余弦定理证明:
;
(2)用正弦定理证明:
;
(3)用向量的方法证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e63471f592531e46277365ed319e2acc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e17f388fec2cc99288248801962c266b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5ce2f54d69a5987c1de19da53342811.png)
(1)用余弦定理证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e63471f592531e46277365ed319e2acc.png)
(2)用正弦定理证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e17f388fec2cc99288248801962c266b.png)
(3)用向量的方法证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5ce2f54d69a5987c1de19da53342811.png)
您最近一年使用:0次
解题方法
8 . 在
中,角A,B,C的对边分别为a,b,c,已知
.
(1)证明:
;
(2)若
,
,求
的周长和面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c73d455f4ba6a4d1144006fdc79f89c7.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a70d8f920d57c9c3f9cbffaf45c4055.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65397f11ea8af736f38debadf420c4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d2c413253fe5bc1f9287a35e6fc45eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次
解题方法
9 . 在
中,内角
的对边分别为
,且
.
(1)求
的值;
(2)记
的面积为
,点
是
内一点,且
,证明:
①
;
②
.
![](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/3bb2ba2dbca9bb4261d6af5daedcfa09.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e71cd32a9a68ebcc12ced20abcb2f89.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec15e5cb6d4dc2cf6ba0bedd87514448.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/132934e7b441ecb7bd8d6c2fa099a418.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e40834b0ca6495ea903d115454618efc.png)
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解题方法
10 . 记锐角△ABC的内角A,B,C的对边分别为a,b,c,已知
.
(1)证明:
;
(2)若AD是BC边上的高,且
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b656a189f00fcd69721e107d31cadcc0.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37238084e3ac028b0378bff6ab377c8b.png)
(2)若AD是BC边上的高,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d73556f3870c2f38afafb4c1821cdb56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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