名校
解题方法
1 . 如图1,四边形ABCD中,∠ABC=∠ADC=90°,AD=CD.
(1)求证:BD平分∠ABC;
(2)如图2,点E、F分别在AB、BC上,连接EF,M是EF的中点,过M作EF的垂线交BD于P.求证:AE+CF=
PD;
(3)如图3,在(2)条件下,连AF,若AE=CF,∠DAF=2∠AFE=2α,AF=13,BC=12
,(BC>AB).求BD的长.
(1)求证:BD平分∠ABC;
(2)如图2,点E、F分别在AB、BC上,连接EF,M是EF的中点,过M作EF的垂线交BD于P.求证:AE+CF=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
(3)如图3,在(2)条件下,连AF,若AE=CF,∠DAF=2∠AFE=2α,AF=13,BC=12
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://img.xkw.com/dksih/QBM/2020/3/29/2429921270185984/2431643953848320/STEM/a11d0763769f42568c3d129f4cfc8d4d.png?resizew=550)
您最近一年使用:0次
2020-03-31更新
|
341次组卷
|
2卷引用:黑龙江省哈尔滨市第十七中学2018-2019学年八年级下学期期中数学试题
19-20九年级上·浙江杭州·期末
2 . 定义:有一个角是其对角一半的圆的内接四边形叫做圆美四边形,其中这个角叫做美角.
(1)如图1,若四边形
是圆美四边形,则美角
______度.
(2)在(1)的条件下,若
的半径为10.
①求
的长.
②如图2,在四边形
中,若
平分
,求证:
.
(3)在(1)的条件下,如图3,若
是
的直径,用等式直接写出线段
,
,
之间的数量关系.
(1)如图1,若四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2a8bf5e05a07c93a7104839fc21849.png)
(2)在(1)的条件下,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
②如图2,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07f56f30601dd90379b8a34e05f6ec7b.png)
(3)在(1)的条件下,如图3,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/2020/3/25/2427096204886016/2427185871798272/STEM/4cc3d27231a54dad88c43e53d1b5fbbb.png?resizew=474)
您最近一年使用:0次
3 . 如图,
是⊙
的直径,点
分别在两个半圆上(不与点
重合),
的长分别是关于
的方程![](https://staticzujuan.xkw.com/quesimg/Upload/formula/459d16780ad0e11ae47b975cc520e552.png)
的两个实数根.
(1)
的值为_____ ;
(2)连接
三者之间的等量关系为_____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.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/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28a77aa6c27acfffcc601d9ca7e6d4c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/459d16780ad0e11ae47b975cc520e552.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/771df37a312dac1fb332a31a10340c29.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/415bf3ea3d90f2d395a3889eb2f8a20a.png)
![](https://img.xkw.com/dksih/QBM/2020/3/12/2417878889496576/2418432647446528/STEM/ae4211c3b2b24a59971d92ffc997e517.png?resizew=134)
您最近一年使用:0次
4 . 定义:如果三角形的两个内角
与
满足
,那么称这样的三角形为“类直角三角形”.
尝试运用
(1)如图1,在
中,
,
,
,
是
的平分线.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/7/382bb51a-06a3-4ebd-8932-6d461f62e1d6.png?resizew=169)
①证明
是“类直角三角形”;
②试问在边
上是否存在点
(异于点
),使得
也是“类直角三角形”?若存在,请求出
的长;若不存在,请说明理由.
类比拓展
(2)如图2,
内接于
,直径
,弦
,点
是弧
上一动点(包括端点
,
),延长
至点
,连结
,且
,当
是“类直角三角形”时,求
的长.
![](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/6672c6ca20dc4035ec15d8783f57a5e6.png)
尝试运用
(1)如图1,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87fd28b8b2bde9de5630a6106a6f762e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3262fc038bbec5e7c8cc47df08bef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f08273d339dc5ddbb89aa67bb8205e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/7/382bb51a-06a3-4ebd-8932-6d461f62e1d6.png?resizew=169)
①证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db5e1441a49e782ff0ef46e776cde06a.png)
②试问在边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc3814287dbb60d478bffc5366f9928b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
类比拓展
(2)如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db5e1441a49e782ff0ef46e776cde06a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f25936291abb6432ed5a710ebf0ea195.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecf7679c8b4b1e442ce4286d4b0e9c32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7266b89f8d360083480ad02484520526.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/7/64e8da47-5040-4eb1-af98-a97ab9b13a44.png?resizew=151)
您最近一年使用:0次
5 . 在
中,
,
,在
外有一点
,且
,则
的度数是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b10134e7a46e6f6f7cb9d5e2371727d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3262fc038bbec5e7c8cc47df08bef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ada25f76504c3fd1226da43c94cb4277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66efb2e5b7aa63e8561be256d691fc88.png)
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6 . 阅读下列材料,并完成相应的任务.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/6/406c4208-1795-4599-9ecd-dae2fcbba09f.png?resizew=684)
任务:
(1)上述证明过程中的“依据1”和“依据2”分别指什么?
依据1:
依据2:
(2)当圆内接四边形ABCD是矩形时,托勒密定理就是我们非常熟知的一个定理: (请写出定理名称).
(3)如图(3),四边形ABCD内接于⊙O,AB=3,AD=5,∠BAD=60°,点C是弧BD的中点,求AC的长.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/6/406c4208-1795-4599-9ecd-dae2fcbba09f.png?resizew=684)
任务:
(1)上述证明过程中的“依据1”和“依据2”分别指什么?
依据1:
依据2:
(2)当圆内接四边形ABCD是矩形时,托勒密定理就是我们非常熟知的一个定理: (请写出定理名称).
(3)如图(3),四边形ABCD内接于⊙O,AB=3,AD=5,∠BAD=60°,点C是弧BD的中点,求AC的长.
您最近一年使用:0次
7 . 如图1,矩形ABCD中,∠ACB=30°,将△ACD绕C点顺时针旋转α(0°<α<360°)至△A'CD'位置.
(1)如图2,若AB=2,α=30°,求S△BCD′.
(2)如图3,取AA′中点O,连OB、OD′、BD′.若△OBD′存在,试判定△OBD′的形状.
(3)当α=α1时,OB=OD′,则α1=_____°;当α=α2时,△OBD′不存在,则α2=_______°.
(1)如图2,若AB=2,α=30°,求S△BCD′.
(2)如图3,取AA′中点O,连OB、OD′、BD′.若△OBD′存在,试判定△OBD′的形状.
(3)当α=α1时,OB=OD′,则α1=_____°;当α=α2时,△OBD′不存在,则α2=_______°.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/29/6b0b549b-df56-49d8-a719-8f8546dfa8fe.png?resizew=521)
您最近一年使用:0次
2020-02-11更新
|
665次组卷
|
8卷引用:湖北省武汉市江岸区武汉七一华源中学2019-2020学年九年级上学期12月月考数学试题
湖北省武汉市江岸区武汉七一华源中学2019-2020学年九年级上学期12月月考数学试题2020年天津市和平区部分中学中考数学模拟试题2021年江苏省南京市九年级数学中考模拟试题(已下线)专题2.39 几何模型专题(四点共圆)-2023-2024学年九年级数学上册基础知识专项突破讲与练(苏科版)(已下线)专题3.9 圆的常用辅助线及作法四大题型-2023-2024学年九年级数学上册举一反三系列(浙教版)(已下线)专题24.11 圆的常用辅助线及作法四大题型-2023-2024学年九年级数学上册举一反三系列(人教版)(已下线)专题2.11 圆的常用辅助线及作法四大题型-2023-2024学年九年级数学上册举一反三系列(苏科版)(已下线)专题24.45 几何模型专题(四点共圆)-2023-2024学年九年级数学上册基础知识专项突破讲与练(人教版)
2019·江西·一模
8 . 如图,四边形ABCD内接于
,
,
的半径为5.
(1)如图,连接BD,求BD的长;
![](https://img.xkw.com/dksih/QBM/2020/2/7/2394072551596032/2394735005589504/STEM/57e12caf8d2a4a65a9e4cb0d91333842.png?resizew=76)
(2)如图,连接CA,若CA平分
,求
的最大值;
![](https://img.xkw.com/dksih/QBM/2020/2/7/2394072551596032/2394735005589504/STEM/1f046e338eb345f28f96aa1ac05f5ebd.png?resizew=65)
(3)如图③,若AC为
的直径,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c58a56f775d9ac8da66521ec7e585a7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(1)如图,连接BD,求BD的长;
![](https://img.xkw.com/dksih/QBM/2020/2/7/2394072551596032/2394735005589504/STEM/57e12caf8d2a4a65a9e4cb0d91333842.png?resizew=76)
(2)如图,连接CA,若CA平分
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5865949e0e19e9b9ca8bf0277eb27e13.png)
![](https://img.xkw.com/dksih/QBM/2020/2/7/2394072551596032/2394735005589504/STEM/1f046e338eb345f28f96aa1ac05f5ebd.png?resizew=65)
(3)如图③,若AC为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d9f2d1afd025ca14ed55655ad4ef128.png)
![](https://img.xkw.com/dksih/QBM/2020/2/7/2394072551596032/2394735005589504/STEM/59a6148182ec4f009754782f0abdce7a.png?resizew=73)
您最近一年使用:0次
2019·安徽·一模
9 . 如图,
是
的外接圆,
的外角
的平分线交
于点E,连接CE、BE.
(1)求证:
;
(2)若
,
,求劣弧BC的长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/721c75fcd58d3d54260aad0f82e09e37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/27/b3b6dbaa-04e0-429b-8f8d-e65040ef3ea1.png?resizew=141)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a702c324e0c76150540c3d32df802077.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c646c683fbe522edb7ea54fd3ad873d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ffc2817fa590affb5a760a25dc65308.png)
您最近一年使用:0次
名校
10 . 如图,AB为⊙O的直径,点C、D都在⊙O上,且CD平分∠ACB,交AB于点E.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/15/2c730c06-35da-4b5c-a7cc-c1f51684a202.png?resizew=166)
(1)求证:∠ABD=∠BCD;
(2)若DE=13,AE=17,求⊙O的半径;
(3)DF⊥AC于点F,试探究线段AF、DF、BC之间的数量关系,并说明理由.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/15/2c730c06-35da-4b5c-a7cc-c1f51684a202.png?resizew=166)
(1)求证:∠ABD=∠BCD;
(2)若DE=13,AE=17,求⊙O的半径;
(3)DF⊥AC于点F,试探究线段AF、DF、BC之间的数量关系,并说明理由.
您最近一年使用:0次
2020-01-18更新
|
733次组卷
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11卷引用:江苏省南通市部分学校联考2019-2020学年九年级上学期期中数学试题
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