名校
1 . 在直角
中,
,
,
是
边上一动点,连接
,以
为边在
的右侧作一个等边
,连接
.
平分
时,证明
是等边三角形;
(2)如图2,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8575912bebb3106ad40918ad4c30bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cca121a2e8b03262a1e8b2508f1c6f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefe4a3e7a7fa195ed6a6712447639b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6b41d4070854edfaa24071137b314cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63b80f6162fd1dbff226cfcb0f07f5c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fe59deb5eff9123704c5505830b597e.png)
(2)如图2,证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a929f9a63546fe3bcf6f97d80147f809.png)
您最近一年使用:0次
名校
2 . 如图,在
中,
,
的垂直平分线交
于点
,交
于点
,
的周长等于
,则
的长度为 _____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e136e41017509ceb516aa8e261cc28c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1a9c6a736e6eac98a676fa3232db5a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1a9c6a736e6eac98a676fa3232db5a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3dc12fd638cffc9d0f1daf001b405eec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45e61680ffc6f940bd5b8afda3ae9c59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
您最近一年使用:0次
名校
3 . 在联欢会上,有A、B、C三名选手站在一个三角形的三个顶点位置上,他们在玩“抢凳子”游戏,要求在他们中间放一个木凳,谁先抢到凳子谁获胜,为使游戏公平,则凳子应放的最适当的位置是在
的( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
A.三边中垂线的交点 | B.三边中线的交点 |
C.三条角平分线的交点 | D.三边上高的交点 |
您最近一年使用:0次
名校
4 . 如图所示是一条线段,
的长为
厘米,
的长为
厘米,假设可以随意在这条线段上取一个点,那么这个点取在线段
上的概率为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f43677db00ba65a7f96fc49627d70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa29fe6cd9eb51c184f6299d437375cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa29fe6cd9eb51c184f6299d437375cb.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
名校
5 . 下列图形中是轴对称图形的是( )
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
名校
6 . 如图,在
中,
,点F在线段
上,连接
,延长
至点D,连接
,满足
,点H是线段
上一动点(与点B,C不重合),连接
交
于点E,交
于点G.
,求
的长;
(2)如图2,若
,猜想
与
的数量关系,并证明你猜想的结论;
(3)如图3,在(1)的条件下,点P是
内一点,连接
,满足
,是否存在点P,H,使得
最小,若存在,请直接写出
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d54cb14e377e3474e97365fc0e15f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0448ba96d216281134fe66c96bfcde5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7e4fa04825ac7d071968056322d88be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d02c3ddde8c965b76ed994cb1d2b8864.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
(2)如图2,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/096d344d01f2546d495b17318f7bb9ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6655e2fa64a32cd12fe0279afd65d73.png)
(3)如图3,在(1)的条件下,点P是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b506b0941433a6a5d5387d0ec95596ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01bf6b6babd99a7590d2f4d950550ea7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a49f79c156b544fd025978156e404c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02a549dd4a43edfdaff0eeb051fa3dde.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02a549dd4a43edfdaff0eeb051fa3dde.png)
您最近一年使用:0次
名校
7 . 如图1,抛物线
经过点
,与y轴交于点C,直线l:
经过点C,与抛物线交于点A,与x轴交于点B.
(2)点P为直线l上方抛物线上一点,作
于点Q,求
的最大值以及此时点P的坐标.
(3)如图2,将抛物线
沿着射线
方向平移
个单位得到抛物线
,
与x轴分别交于点D、点E,与y轴交于点F,连接
,
与
对称轴交于点N.点M是抛物线
对称轴上一点,当
时,求点M的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58d88bbd34102b55fa928e8ff83f0d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd94a63c5871b5b4356779d03fcb4694.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d85aa11161991637e496bc9d500371ca.png)
(2)点P为直线l上方抛物线上一点,作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5b9d83969b6a8e27e57ab71b34e2b81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14c3d6a6b335fc92978c586364e9ed4a.png)
(3)如图2,将抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58d88bbd34102b55fa928e8ff83f0d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280757052d9b68ac5b8dd95fcd329644.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b4d2174f411d9db6ab7b2aea47818cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b4d2174f411d9db6ab7b2aea47818cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b4d2174f411d9db6ab7b2aea47818cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b4d2174f411d9db6ab7b2aea47818cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46af7d340ed055c3987535986d3251c2.png)
您最近一年使用:0次
名校
8 .
年
月
日,是四川汶川地震
周年纪念日,也是我国第
个“防灾减灾日”.为了解学生对“防灾减灾知识的了解程度,某校随机抽取了八年级、九年级各
名学生进行网上问卷测试,并对得分情况进行整理和分析(得分用整数
表示,单位:分),且分为
,
,
三个等级,分别是:优秀为
等级:
,合格为
等级:
,不合格为
等级:
.分别绘制成如下统计图表.
其中八年级学生测试成绩数据的众数出现在
等级,
等级测试成绩情况分别为:
,
,
,
,
,
,
,
,
,
,
;
九年级学生测试成绩数据为
等级共有
个人.
根据以上信息,解答下列问题:
(1)填空:
_______,
_______,
_______;并补全八年级抽取的学生测试成绩频数分布方图;
(2)根据以上信息,你认为该学校哪个年级的测试成绩更好,并说明理由(写出一条理由即可);
(3)若该校八、九年级分别有
名学生,请估计该校八、九年级学生中成绩为优秀的学生共有多少名?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8e8936c9fe1e81726455908657a29fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8da45c443af7994a26ffa9d8894e7262.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c748e40ba21ac5063d3bccaa57ef278.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c748e40ba21ac5063d3bccaa57ef278.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b7f27ebcef70a3ebbbe8d2e53ea0896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.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/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fd6398a2768bade390cd738a5f1ba82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5c566708e737c676e3d69674174751b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd33b307a85f0627755433c7c4f48c34.png)
其中八年级学生测试成绩数据的众数出现在
![](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/86608326541db75771f5de9db6187e6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cbcf82603580ddba4cfdb4efde85a8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4500d4031cbf22a456fa09fa393ba2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cbcf82603580ddba4cfdb4efde85a8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/796e3e32d29652fb3ed9984c414aec35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ef0a9f421547e737ec464d29b314403.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/796e3e32d29652fb3ed9984c414aec35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41a83b0895127ee97d27b3d89a4403dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cbcf82603580ddba4cfdb4efde85a8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ef0a9f421547e737ec464d29b314403.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc165d29cf2cbee79a73f485354a03e6.png)
九年级学生测试成绩数据为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
年级 | 平均数 | 中位数 | 众数 |
八年级 | |||
九年级 |
(1)填空:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ccd4162c7d09f970cb77cadacdbe521.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4e9bb42376c12d7d21702ae8062b25a.png)
(2)根据以上信息,你认为该学校哪个年级的测试成绩更好,并说明理由(写出一条理由即可);
(3)若该校八、九年级分别有
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35a87e5643f2f605c39a0f663e7010cf.png)
您最近一年使用:0次
名校
9 . 如图,在四边
中,
,
是对角线.
的垂直平分线
,
分别交
,
于点O,E,F.连接
.(只保留作图痕迹)
(2)在(1)问所作的图形中,求证:四边形
为菱形.(请完成下面的填空)
证明:∵
垂直平分![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
∴①______,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c672f693a7e75a7bae4936dcb1920430.png)
∵![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dceb5cc71fc50f20649f6b9535fd914.png)
∴②______
∵在
和
中![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5836c0e65df9687060ed93ec0ecd6a1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/068d9dc3d417e2c7e10f655b97bd265f.png)
∴
,∵![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c940869dd66321d1132828a95cb5353.png)
∴四边形BFDE为平行四边形
∵④______
∴四边形BFDE为菱形(对角线垂直的平行四边形为菱形)
在作图过程中,进一步研究还可发现,夹在一组平行线间的线段的垂直平分线与平行线相交后,可以得到一个特殊四边形,请你依照题意完成下面命题:夹在一组平行线间的线段的垂直平分线与平行线相交后⑤______.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dceb5cc71fc50f20649f6b9535fd914.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11944f055fd806016ae3576019d4bf30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf22927eb6819a02978ef0c6b101f6f5.png)
(2)在(1)问所作的图形中,求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c87e1fe20bb0e8292e993657e14bc79a.png)
证明:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
∴①______,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c672f693a7e75a7bae4936dcb1920430.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dceb5cc71fc50f20649f6b9535fd914.png)
∴②______
∵在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf81da91f4f486850d143c5963abc13f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ac0b5d17fa816eaccc1bac76e03180e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5836c0e65df9687060ed93ec0ecd6a1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/068d9dc3d417e2c7e10f655b97bd265f.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcf2e3236ea30ee2c37928b98041f13a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c940869dd66321d1132828a95cb5353.png)
∴四边形BFDE为平行四边形
∵④______
∴四边形BFDE为菱形(对角线垂直的平行四边形为菱形)
在作图过程中,进一步研究还可发现,夹在一组平行线间的线段的垂直平分线与平行线相交后,可以得到一个特殊四边形,请你依照题意完成下面命题:夹在一组平行线间的线段的垂直平分线与平行线相交后⑤______.
您最近一年使用:0次
名校
10 . 计算:
(1)
;
(2)
.
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2641bcd18eb111f77559c517ec64a462.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93a702788c76ac73ab724504570bb03d.png)
您最近一年使用:0次