1 . 阅读与思考
下面是小宇同学的数学日记,请你仔细阅读并完成相应的任务.
圆内接正三角形的有趣结论
我在学完“圆内接正多边形”之后,知道了圆内接正多边形有许多有趣的结论.于是,我通过查阅资料发现了一个与圆内接正三角形相关的结论.
如图1,等边三角形
内接于
,点P是弧
上的任意一点,连接
,可得
下面是这个结论的证明过程:
为顶点,作
,
交
于点D,
在等边三角形
中,
,
,
(依据),
,
是等边三角形,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2de0d10ef8b748d4531250c37c5d3f9e.png)
,
∵
,
∴
,
即
,
∴
,
∴
,
∵
,
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e58d9a2a7bebbf0f46e107befc9e329.png)
任务:
(1)小宇的日记中的“依据”是 ,
(2)如图,若
,
,则线段
的长度是 ,
内接于
,点
是弧
上的任意一点,连接
,则
之间有怎样的数量关系?请说明理由.
下面是小宇同学的数学日记,请你仔细阅读并完成相应的任务.
圆内接正三角形的有趣结论
我在学完“圆内接正多边形”之后,知道了圆内接正多边形有许多有趣的结论.于是,我通过查阅资料发现了一个与圆内接正三角形相关的结论.
如图1,等边三角形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67e06899dd89bc052bccd6743613412f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30a52d61c1052ebb6d4cc5211305c83b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddf6a384d9e93507c64a311a3b96d4c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
在等边三角形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3570a95f68349fcd9417fcda62e78e7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db14714995d404fc3cc36b5d5c24def1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69bc2d2f642acf81e233bd44d10de3d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8a4188be6aa9fd2b54b90ef3a753007.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/888ea50240faf9e50e094e320ca4ff2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2de0d10ef8b748d4531250c37c5d3f9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbf3f1d17f0e951629e26ab409638834.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7a39bb5b63201b366d94019fb0145c6.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ee5f1700f0d998930fb817eb71e01d9.png)
即
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99f7d1ab59e19eb5319ca9c07eb65cf4.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70bfd26dc978c7373f7b976d813f7e6e.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d973180e84919e846c7011e7aea22079.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d29663ae6d94d72607bf29200e4e7ca2.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e58d9a2a7bebbf0f46e107befc9e329.png)
任务:
(1)小宇的日记中的“依据”是 ,
(2)如图,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b480dda3eea0e0b3391890efcb783b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24d309a79c0e9dd097d661e3c150d517.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30513ea48bc1ef3ae78adac83d894f14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67e06899dd89bc052bccd6743613412f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67e06899dd89bc052bccd6743613412f.png)
您最近一年使用:0次
2 . 如图,四边形ABCD中,
,E为射线CB上的动点,将线段AE绕A点顺时针旋转
得到
.设
的面积为S.
(1)当
时,求
的长;
(2)当
时,求S关于x的函数表达式;
(3)求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be791428a8714fcaaf468d1199e4966f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bf97f9082d7f40bc680cc2c58865309.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fbc691de48937fbce2710955a93dd31.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/27/0e06cbe0-b1a1-45e6-bb3e-829df8223c9c.png?resizew=261)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55aa0a20848c37c1892c567b2315e04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926d2094777538ba6a70ea65d5061ef7.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ad2b31cfb9939e45bdb29af8139af06.png)
(3)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45d30252720ff0a2b1f105523e9aa3b4.png)
您最近一年使用:0次
2024-04-01更新
|
77次组卷
|
2卷引用:2023年江苏省无锡市中考数学模拟预测题(副卷)
3 . 在
中,
,
,
,D为
的中点,P为
边上一点,将
绕点D逆时针旋转
得线段
,点P的对应点是点Q,当A、Q、D三点在同一直线上时
的长为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3262fc038bbec5e7c8cc47df08bef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab926d89b65f26c12e3da73ef1e5cf68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef0402dd5ae3db10281f9f1e11738bcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fd17a66a2af938c89e46f22e4d893b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3525ddc5153fada64eaf14e50b536542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/29/768d1d7c-08d0-451e-8260-dde4662f7ee2.png?resizew=84)
您最近一年使用:0次
4 . 如图,
,
,点
在
上.
平分
;
(2)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4009aa13093cc3865dcd51b371892160.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba11242dcc61d3c7c3555b598b5fdc89.png)
您最近一年使用:0次
5 . 如图是由小正方形组成的
网格,每个小正方形的顶点叫做格点,图中
都是格点,
是
上一点.仅用无刻度的直尺在给定网格中完成画图.
,先画点
,使四边形
为平行四边形,连接
,再画
的中点
;
(2)如图
,若
是
与网格线的交点,先画点
绕点
逆时针旋转
的对应点
,再在
上画点
,使得
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fed892d056a84412355770243b5faf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8c3e7483ce8b396d4a1a007f9f54812.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1d70fb53a3bc46be3e6365f5ed26496.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c2293f93791a597bf0162411f3395f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c2293f93791a597bf0162411f3395f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
(2)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88c5465401ee0d0d863481e7210f6d8a.png)
您最近一年使用:0次
2024-03-29更新
|
239次组卷
|
2卷引用:江苏省镇江市丹阳市2023-2024学年九年级下学期期中数学试题
6 . 如图,点
,
,
,
在同一直线上,点
,
在
的两侧,
,
,
..
![](https://img.xkw.com/dksih/QBM/2024/3/24/3460407604142080/3462053670109184/STEM/97392fbdb0dd4eaeafd0cb268728bc5f.png?resizew=151)
(1)求证:
;
(2)若
,
,求
的度数.
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c220eadc312101e2fb89dfe920f7b30d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c55ee522f41c43253050e92b3c8de31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0fff774b4b0087a6f304ce930d359be.png)
![](https://img.xkw.com/dksih/QBM/2024/3/24/3460407604142080/3462053670109184/STEM/97392fbdb0dd4eaeafd0cb268728bc5f.png?resizew=151)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57cfa2fe76009b2ea36df44b1f8bb4d9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff9c78b1255e7239593bcedc22572d59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68e744f480e11f588570c5d6738799f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4598486f8c5ac28b1165b76e78105979.png)
您最近一年使用:0次
名校
7 . 如图,在正方形
中,点B的坐标是
,点E、F分别在边
、
上,
,若
,则F点的纵坐标是________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3241d7fedd89d85711acd7a2635298af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9ac2dcdbe2eaecf94bb27cd76107624.png)
![](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/348fb71fbc47fd87e9ce011652ef4186.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee480d748f36c1b43e941384dd41f13e.png)
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2024-03-28更新
|
223次组卷
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5卷引用:数学(无锡卷)-【试题猜想】2024年中考考前最后一卷
数学(无锡卷)-【试题猜想】2024年中考考前最后一卷江苏省苏州市震泽中学小杨班2023-2024学年八年级下学期数学三月份学情调研试题(已下线)江苏省八年级下学期期中必刷压轴60题(27个考点专练)-2023-2024学年八年级数学下学期考试满分全攻略高频考点+重难点讲练与测试(苏科版)广西壮族自治区南宁市青秀区天桃实验学校2023-2024学年八年级下学期4月期中数学试题广西南宁市天桃实验学校教育集团2023-2024学年八年级下学期期中数学试题
8 . 如图,在平面直角坐标系中,点A在y轴上,且,点M为x轴上的一个动点,连接
,将线段
绕点A逆时针旋转
至线段
,连接
,则
的最小值为
您最近一年使用:0次
9 . 如图,将线段
绕点B逆时针旋转
得到线段
,点D是平面内一动点,且D、B两点之间的距离为5,连接
、
,则
的最小值为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e364cd2e4a83ff75d8cdcedb6d2c63da.png)
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2024-03-26更新
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290次组卷
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5卷引用:2024学年江苏省盐城市初级中学九年级下学期中考模拟数学模拟预测题
2024学年江苏省盐城市初级中学九年级下学期中考模拟数学模拟预测题2024年江苏省盐城市亭湖区九年级数学中考模拟预测题2024年江苏省盐城市亭湖区中考数学模拟预测题(已下线)查补培优冲刺02 几何最值类综合压轴-【查漏补缺】2024年中考数学复习冲刺过关(江苏专用)广东省清远市英德市2023-2024学年八年级下学期期中数学试题
名校
10 . 如图,正方形
的边长为4,点
分别在边
上,且
平分
,连接
,分别交
于点
是线段
上的一个动点,过点
作
,垂足为
,连接
.有下列四个结论:①
垂直平分
;②
的最小值为
;③
;④
.其中正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cf9b288c48c73463a2f214f02b6952a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edf3c19de60555f4928d1ef1ce99a20e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f56f318087fb698339caacaff1e956db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5157b42da58d55daad27d98b2fec15ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9c00abe2cd9cb334d9ffcdf992c7ab5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17f0d14209ea7c9056268be636afcfe4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a7e4a6765ce78b05ee97764771e01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9887e1ff61308713287d592c8e8d942.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
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A.①② | B.②③④ | C.①③ | D.①③④ |
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