名校
解题方法
1 . 在
中, 角
的对边分别为
, 若
.
(1)求证:
;
(2)对
, 请你给出一个
的值, 使不等式
成立或不成立,并证明你的结论.
![](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/03290185439a3e7332f41ea038f43eaf.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46abdcf989e4e121de989f73340a55f9.png)
(2)对
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0abad0f9bfeee920a0444badf1701a2f.png)
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2 . 下图是小明复习全等三角形时遇到的一个问题并引发的思考,请帮助小明完成以下学习任务.
如图,OC平分
,点P在OC上,M、N分别是
、OB上的点,
,求证:
.
小明的思考:要证明
,只需证明
即可.
证法:如图①:∵OC平分
,∴
,
又∵
,
,∴
,
∴
;
请仔细阅读并完成以下任务:
![](https://img.xkw.com/dksih/QBM/2022/5/3/2971556652843008/2974950110486528/STEM/93b06bfd-3171-47a5-9d77-19e02cb916d0.png?resizew=524)
(1)小明得出
的依据是______(填序号).
①SSS ②SAS ③AAS ④ASA ⑤HL
(2)如图②,在四边形ABCD中,
,
的平分线和
的平分线交于CD边上点P,求证:
.
(3)在(2)的条件下,如图③,若
,
,当△PBC有一个内角是45°时,
的面积是______.
如图,OC平分
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2032fccdf9ab12429aae024d67b19d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4acd79bb9fb06f7c806eb6e17e4b613.png)
小明的思考:要证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4acd79bb9fb06f7c806eb6e17e4b613.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94d54326f92838c51a197cc82985e506.png)
证法:如图①:∵OC平分
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c1f18cef1745d84a0265246684753bd.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25ce5cddb3791c46d6ef0c32d35a7886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2032fccdf9ab12429aae024d67b19d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/905a8192e8d6365309562606283e9959.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4acd79bb9fb06f7c806eb6e17e4b613.png)
请仔细阅读并完成以下任务:
![](https://img.xkw.com/dksih/QBM/2022/5/3/2971556652843008/2974950110486528/STEM/93b06bfd-3171-47a5-9d77-19e02cb916d0.png?resizew=524)
(1)小明得出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/905a8192e8d6365309562606283e9959.png)
①SSS ②SAS ③AAS ④ASA ⑤HL
(2)如图②,在四边形ABCD中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/609ada36dd56b33279103ebc1f90bbac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4189a0821a0ffab9dc171ecd279ba442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ed66431681da1db8f7cb0f40cd19201.png)
(3)在(2)的条件下,如图③,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc34db5860990e51ba31edc8cdd077c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afcd54ff42ebdc70cb273cd5909d549f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
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名校
3 . 如图1,在四边形
中,
,
,
,将
沿着
折叠,使得
(如图2),过D作
,交
于点E.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/21/9bc8b8dc-8ded-4e5e-8520-df06cedcb6ce.png?resizew=296)
(1)证明:
;
(2)求
;
(3)求平面
与平面
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b512c0498d251e6859686c657b5be0ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18120a244d3a1f9c1688bf53eb2ad775.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e32513c66bca1e2d1706d50a6615df1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661ff55b5ebbadfb600989af3cfce2fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec9e2a600d4675d510c58b984027e33d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/21/9bc8b8dc-8ded-4e5e-8520-df06cedcb6ce.png?resizew=296)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b757f0c42ae5c9a2d6a4b19e5877b27.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
(3)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
您最近一年使用:0次
2024-03-07更新
|
393次组卷
|
2卷引用:重庆市杨家坪中学2023-2024学年高三下学期第二次月考数学试题
2024·全国·模拟预测
4 . 在
中,点D,E都是边BC上且与B,C不重合的点,且点D在B,E之间,
.
(1)求证:
.
(2)若
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/531f165d0a2cc7290d181c2d46f6037f.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eaffc765d90d879a54c060f051aa108.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ed8169e17a96542e3df21ccaf0c8159.png)
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5 . 在
中,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5603f8d4015567001f41e8f67b148be9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
(1)求证
为等腰三角形;
(2)再从条件①、条件②、条件③这三个条件中选择一个作为已知,使
存在且唯一,求b的值.
条件①:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c7ce7733e861b352bd792c9425852c8.png)
条件②:
的面积为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7163395f9aaa29be7f6b3106ba48b744.png)
条件③:
边上的高为3.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5603f8d4015567001f41e8f67b148be9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
(1)求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)再从条件①、条件②、条件③这三个条件中选择一个作为已知,使
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
条件①:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c7ce7733e861b352bd792c9425852c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32ca6fa9955690cec01db601e3abce0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7163395f9aaa29be7f6b3106ba48b744.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32ca6fa9955690cec01db601e3abce0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
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7日内更新
|
221次组卷
|
2卷引用:北京市第一○一中学2024届高三下学期三模数学试题
名校
解题方法
6 . 记钝角
的内角
的对边分别为
.若
为锐角且
.
(1)证明:
;
(2)若
,求
周长的取值范围.
![](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/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7d1a14022c3488c0ae6f486f6b85957.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b54998c4d2a3a107cd6a392d73e983eb.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6de1d395e6c48c0676a1488a299479d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次
2024·全国·模拟预测
解题方法
7 . 在
中,内角
的对边分别为
,且
,
,
.
(1)求
的面积;
(2)证明:
是钝角三角形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce7af7c5df749c6fa9bbe87faa72c66d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bba1e7a657ed134e68efd159b606620f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fcc480016747ca3595a20507ff3c2c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ce00b4639bbea645aa6341aab4254bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83d672d1dd856e282eb4758c0618597d.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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8 . 在△ABC中,角A,B,C所对的边分别为
,已知
.
(1)求证:
;
(2)若
,求
面积的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88f2599ca8b6b683e57a82699c8b1ebb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6276112f5093e1649a9d31e81237711e.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe282e00c64370cce623eed1433fd5b5.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/175db5169ad8ff039a5e780db96795f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次
2023·全国·模拟预测
解题方法
9 . 在
中,内角A,B,C的对边分别为a,b,c,且
,
.
(1)证明:
是锐角三角形;
(2)若
,求
的周长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bfeaf26f178031f78a5545233a2a73f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f78a4481d0f48bee10af4ebedb9811ad.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e258ab9e600435b37465092243d99f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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2023高三上·全国·专题练习
解题方法
10 . 如图.在平面四边形
中,
.设
,证明:
为定值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a50cfef119ed7a32f22546355225e60a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e062b576227465b4512dd653c3f16d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97b75a84c919154f4fcf4527b9af0f93.png)
![](https://img.xkw.com/dksih/QBM/2023/12/19/3392566498025472/3392592825294848/STEM/4d3e01fd2b6042c58098dfd1312316fd.png?resizew=125)
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