解题方法
1 . 如图1,在
中,
,
,点D,E分别在边AB,AC上,
,连接DC,点M,P,N分别为DE,DC,BC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/8/d3f9bf69-239d-4a2f-afa6-ab13bae095de.png?resizew=392)
(1)观察猜想:图1中,线段PM与PN的数量关系是________,位置关系是________;
(2)探究证明:把
绕点A逆时针方向旋转到图2的位置,连接MN,BD,CE,判断
的形状,并说明理由;
(3)拓展延伸:把
绕点A在平面内自由旋转,若
,
,请直接写出
面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f89deb952f57f4b3fa4887b098b7b91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d212c1709b8e72a055cf1b5381ef64.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/8/d3f9bf69-239d-4a2f-afa6-ab13bae095de.png?resizew=392)
(1)观察猜想:图1中,线段PM与PN的数量关系是________,位置关系是________;
(2)探究证明:把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ed4c4e8edbd179f3fc38a6653f18c1.png)
(3)拓展延伸:把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc11331a7b2d2619b40ee6d34c3bd620.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc34db5860990e51ba31edc8cdd077c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1ed4c4e8edbd179f3fc38a6653f18c1.png)
您最近一年使用:0次
2 . 如图,正方形
的边长为
,
,
分别为边
和
上的点,且
的周长为2.
![](https://img.xkw.com/dksih/QBM/2021/1/6/2630196112523264/2633078219218944/STEM/88df7da9d2d24d72b0261d861cc58b01.png?resizew=174)
(1)求证:
;
(2)求
面积的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31f6c430883f98d3c6502fdb9cb0a64c.png)
![](https://img.xkw.com/dksih/QBM/2021/1/6/2630196112523264/2633078219218944/STEM/88df7da9d2d24d72b0261d861cc58b01.png?resizew=174)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e75b8c50824fbbdb7328b47d9f2b04f.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d53407b42c690396db22f8278be30623.png)
您最近一年使用:0次
名校
3 . 如图,
是平面四边形
的一条对角线,已知
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/f482ed50-9b3d-466e-b5be-9c9671bb8e13.png?resizew=185)
(1)求证:
为等腰直角三角形;
(2)若
,
,求四边形
面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4355c3b7f9a75c91aae33d869f0350b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dcc535649e4f8c842a63d724bfd8cc9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/26/f482ed50-9b3d-466e-b5be-9c9671bb8e13.png?resizew=185)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bb961bd7db3adb76af2d4cedb611bd7.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037b342a682cbd4241855a243da3c016.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
您最近一年使用:0次
2020-02-15更新
|
488次组卷
|
3卷引用:重庆市西南大学附属中学校2020届高三上学期第五次月考(理)数学试题
4 . (1)在
中,内角A,B,C的对边分别为a,b,c,R表示
的外接圆半径.
①如图,在以O圆心、半径为2的圆O中,
和
是圆O的弦,其中
,
,求弦
的长;
②在
中,若
是钝角,求证:
;
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/6/b88cc3d0-c666-487e-9727-d5d16300cd3f.png?resizew=160)
(2)给定三个正实数a、b、R,其中
,问:a、b、R满足怎样的关系时,以a、b为边长,R为外接圆半径的
不存在、存在一个或存在两个(全等的三角形算作同一个)?在
存在的情况下,用a、b、R表示c.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
①如图,在以O圆心、半径为2的圆O中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b83a71cff8e2ed9c2c93ed91a5d48671.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e901c430af74f7bbce43364bd4f2e47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
②在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/194741f4d2ae7ee44cafca780361446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e0c86fd15b7ef641e45e582dd4a58a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/6/b88cc3d0-c666-487e-9727-d5d16300cd3f.png?resizew=160)
(2)给定三个正实数a、b、R,其中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2c659396f6a0f72e213185b1ab2e198.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
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2020-04-17更新
|
1644次组卷
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15卷引用:【全国百强校】福建省福州第三中学2017-2018学年高一下学期(实验班)期末考试数学试题
【全国百强校】福建省福州第三中学2017-2018学年高一下学期(实验班)期末考试数学试题上海市曹杨二中2018-2019学年高一下期末数学试题(已下线)上海市华师大二附中2015-2016学年高一下学期期中数学试题江苏省南通中学2018-2019学年高一下学期期中数学试题江苏省扬州中学2019-2020学年高一下学期6月月考数学试题(已下线)第6章三角(能力提升)-2020-2021学年高一数学下册单元测试定心卷(沪教版2020必修第二册)(已下线)第19讲压轴综合题(讲义)-【教育机构专用】2021年春季高一数学辅导讲义(沪教版2020必修第二册)湖南省怀化市第三中学2020-2021学年高一下学期期中数学试题(已下线)上海期末真题精选50题(大题压轴版)-2020-2021学年高一数学下册期中期末考试高分直通车(沪教版2020必修第二册)(已下线)大题好拿分期中考前必做30题(压轴版)-2020-2021学年高一数学下册期中期末考试高分直通车(沪教版2020必修第二册)(已下线)第20讲 期末复习(练习)提升卷-【教育机构专用】2021年春季高一数学辅导讲义(沪教版2020必修第二册)(已下线)6.4平面向量的应用C卷湖南省长沙市明德中学2021-2022学年高一下学期期中数学试题上海市复旦大学附属中学2022-2023学年高二上学期开学考试数学试题(已下线)第六章 平面向量及其应用(基础、典型、易错、压轴)分类专项训练(3)
解题方法
5 . 在平面四边形
中,已知
,
,
.
(1)若
,
,
,求
的长;
(2)若
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/230f6a04c197e6036b8d3d7680b96ad2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c5d383c419b53ea5159625f306760b9.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27cde33974f1c49a3df4589c00974c99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd244c4ca2ae50d2b87fb221a191fc12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4ee3eb2db791070d3e5269b8f3ba4a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94c905599045694c50d401bfc78c394f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1bdd948550c8b796a4eee38b204f299.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3039c774e00f6520449aa9d4b3c45464.png)
您最近一年使用:0次
2020-03-19更新
|
1854次组卷
|
4卷引用:2020届天一大联考海南省高三年级第一次模拟考试数学试题
2020届天一大联考海南省高三年级第一次模拟考试数学试题【新教材精创】9.1.2余弦定理(第2课时)练习(1)海南省海南枫叶国际学校2019-2020学年高一下学期期中考试数学试题(已下线)第8章 平面向量(章节压轴题解题思路分析)-2020-2021学年高一数学下册期中期末考试高分直通车(沪教版2020必修第二册)
18-19高一下·上海·阶段练习
名校
6 . (1)如图,点
在线段
上,直线
外一点
对线段
的张角分别为
,即
.求证:
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/a5f120f8-b9f6-4433-a27f-6b330676d37d.png?resizew=150)
(2)在
中,
为线段
上一点,
,其中
,试用
表示线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e36b47a1262a6da2885ab50d36dbd9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ba83980a38c5e1fe4be841bc8a51d1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/572323452d4f3651d155007873cc796e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2dd0dd6f8b409e8b08d26be7eea834e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/a5f120f8-b9f6-4433-a27f-6b330676d37d.png?resizew=150)
(2)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9178fc8b5d65aa75fa9196294a0db7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3a3a3d168a18401e47576f70a692e87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/886c99da9a1840ea80297267d3c303d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb3cd66c805956f59e92f40dbaa01203.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8074bde6e03046a22f6310a4199518e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
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名校
7 . 在
中,
,
.
(1)求证:
平分
;
(2)当
时,若
,
,求
和
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2ec7b39ec6b2bbfc75a2138f601f6d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54118d72fe21da443757dafab5cdf3ef.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3cf0f585938ede9eca890a6eb326d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4aca5534bce25acaeb7379deed8f8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/650c83513f6ffe5615f64dd11be333ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
您最近一年使用:0次
2018-08-27更新
|
1212次组卷
|
4卷引用:【全国百强校】河南省信阳高级中学2018届高三高考模拟二数学(理)试题
【全国百强校】河南省信阳高级中学2018届高三高考模拟二数学(理)试题四川省泸州市泸县第四中学2019-2020学年高一下学期期中考试数学试题陕西省西安市铁一中学2023-2024学年高三上学期9月月考理科数学试题(已下线)陕西省西安市铁一中学2023-2024学年高三上学期第一次月考理科数学试题
名校
8 . 三角是你高一学的吧,想当初你刚入高中,那么青涩,经过军训,经过红歌会,经过运动会,经过春游,经过无数次考试的洗礼,你已经长大了.在
中,
,
.
(1)求证:
是直角三角形;
(2)若点
在
边上,且
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b903021571c1b57943a1a3274217654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75660afc16201218fb61f3f2df34caf3.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62a50d3b893c9eb00791c230f99c5721.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
您最近一年使用:0次
9 . 在
中,角
所对的边分别为
,
;
(1)证明:
为等腰三角形;
(2)若
为
边上的点,
,且
,
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38335830b93ac4d99c28a8e209eecb3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7f5573b30734d65648f61c0a94c98de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea2475ac5795832dfe8ff0b3c6771693.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b6bef27de230acad352f25e954f4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/492740af1308d48fb2894ed03ae940c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65397f11ea8af736f38debadf420c4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
您最近一年使用:0次
2018-11-27更新
|
2301次组卷
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12卷引用:【区级联考】广东省佛山市顺德区2019届高三第二次教学质量检测理科数学试卷
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10 . 如图,在四边形
中,
.
(Ⅰ)求
的长;
(Ⅱ)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfbdf57dd6e2d0bd7f76aedb946a7f51.png)
(Ⅰ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
(Ⅱ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5a483c03dfd6bc9710f327f8722df28.png)
![](https://img.xkw.com/dksih/QBM/2018/5/17/1947519263055872/1948892277817344/STEM/aa48f731-0e37-43ec-a8f9-a51e7f9ccdaa.png?resizew=180)
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