1 . 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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2 . 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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2024-06-14更新
|
263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
3 . 如图,在山脚
测得山顶
的仰角为
,沿倾斜角为
的斜坡向上走
米到
,在
出测得山顶
得仰角为
,
,求坡面的坡比.(坡比是坡面的垂直高度与水平宽度的比值)
(2)求证;山高
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f435efcc7869eec21bdba1ed81dc3f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a3f9f6f08449a598c3a4e156bdcec45.png)
(2)求证;山高
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1582059edd9bd52b77b5f8a97c2039a.png)
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名校
解题方法
4 . 已知锐角
中,角
,
,
所对的边分别为
,
,
,其中
,
,且
.
(1)求证:
;
(2)已知点
在线段
上,且
,求
的取值范围.
![](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/36e15cbd7c42d7b15d7ba8d2b28ab8df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/084399e0edc1c3bfb33b338987dcfa5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098943e98ad321740f83f0bb67004598.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f44c181a2f6ae22d5d52b374768dc57.png)
(2)已知点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99eab3edfe4687c78c290b7e7e5e0cbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
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2024-05-11更新
|
1196次组卷
|
3卷引用:陕西省安康市高新中学、安康中学高新分校2024届高三下学期模拟预测数学(文科)试题
2024·全国·模拟预测
5 . 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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6 . 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)
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名校
解题方法
7 . 在锐角△ABC中,角A,B,C所对的边分别为a,b,c,已知
,且
.
(1)求证:
;
(2)若
的平分线交AC于D,且
,求线段BD的长度的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07ac99c98d7fd621dbb6595d824c28cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098943e98ad321740f83f0bb67004598.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f44c181a2f6ae22d5d52b374768dc57.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22a688b51f4862f610d3064199aeb336.png)
您最近一年使用:0次
2024-03-13更新
|
1645次组卷
|
6卷引用:河南省济洛平许2024届高三第三次质量检测数学试题
2024·全国·模拟预测
解题方法
8 . 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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名校
解题方法
9 . 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)
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2023·全国·模拟预测
解题方法
10 . 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)
您最近一年使用:0次