1 . 如图,已知点
是平行四边形
对角线
上的点,连接
,过点
在平行四边形内部作射线
交
于点
,且使
,连接
、
,证明四边形
是平行四边形.解答思路:利用平行四边形的性质得到线段和角相等,再通过
与
全等得边角关系,然后利用一组对边平行且相等使问题得到解决.请根据解答思路完成下面作图与填空:
(1)尺规作图:过点
在平行四边形内部作射线
交
于点
,且使
,连接
、
(保留作图痕迹,不写作法与证明);
(2)证明:∵四边形
是平行四边形,
∴
① ,
,
∴
②
在
与
中,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57fe5dd2076e867091f76ab1933f476.png)
∴
,
∴ ③
,
,
∴ ④ .
∴四边形
是平行四边形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10b85b80faacc025432902f23e0e6328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c87e1fe20bb0e8292e993657e14bc79a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d4ce3f962c91f0d3c7b998b5fbb37b5.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/13/e0b0db79-9434-47be-a0fc-9f56c6ec25f2.png?resizew=180)
(1)尺规作图:过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10b85b80faacc025432902f23e0e6328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
(2)证明:∵四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9f63d194aa0d4091618b6f41f569ee2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32e910dce5a57ff0d917e0b4dd620214.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d4ce3f962c91f0d3c7b998b5fbb37b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57fe5dd2076e867091f76ab1933f476.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5678d84003aa65600ea6ab585ef51f1.png)
∴ ③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6205d261fa971443800a46da551253d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2b4ab2a78043a634daa576c6f098faf.png)
∴ ④ .
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f3c15b30bd155641e548a7d8c172dd4.png)
您最近一年使用:0次
2 . 如图,在
中,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/c26f151d-4ae2-44f3-862b-25026d6c8f61.png?resizew=159)
(1)尺规作图:按要求完成下列作图,不写做法,保留作图痕迹,并标明字母.作
的平分线交
于点F,连接
、
;
(2)在(1)的条件下,若
,
,求
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3570a95f68349fcd9417fcda62e78e7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d42218a68301d770accaaefb96b19f8a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/c26f151d-4ae2-44f3-862b-25026d6c8f61.png?resizew=159)
(1)尺规作图:按要求完成下列作图,不写做法,保留作图痕迹,并标明字母.作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
(2)在(1)的条件下,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b1164750466d461f0a415d3a6407589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aea80060d179ec1e88b0db7d88c13a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adcae9d00980803e5955228d1e217abe.png)
您最近一年使用:0次
3 . 某市为了解初中生每天完成作业的时间,在全市范围内随机抽取部分学生进行抽样调查(时长用
表示,单位是小时,共分4组,
:
,
:
,
:
,
:
),统计结果如图所示:
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/13/d8f2913c-eed3-49b2-b74b-3f5768e55bad.png?resizew=377)
(1)这次抽样共调查了______名学生,并补全条形统计图;
(2)所抽取的这部分学生每天完成作业时长的中位数应位于______组;
(3)计算扇形统计图中表示每天完成作业时长在
组的对应的扇形圆心角度数为_____°
(4)若全市共有40000名初中生,请据此估计全市范围内初中生每天完成作业时长不超过2小时的学生人数.
![](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/5a79d7f73b6128650bf7aed538260c72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fe7973e427b05c8301328d24aab43ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a26be643ca599285a5a54d0dd0f200f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c0aa2ef928b6e3341d0a0dc6d8055b9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/13/d8f2913c-eed3-49b2-b74b-3f5768e55bad.png?resizew=377)
(1)这次抽样共调查了______名学生,并补全条形统计图;
(2)所抽取的这部分学生每天完成作业时长的中位数应位于______组;
(3)计算扇形统计图中表示每天完成作业时长在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(4)若全市共有40000名初中生,请据此估计全市范围内初中生每天完成作业时长不超过2小时的学生人数.
您最近一年使用:0次
真题
解题方法
4 . 连接抛物线上任意四点组成的四边形可能是___________ .(填写所有正确选项的序号)
①菱形;②有3条边相等的四边形;③梯形;④平行四边形;⑤有一组对角相等的四边形.
①菱形;②有3条边相等的四边形;③梯形;④平行四边形;⑤有一组对角相等的四边形.
您最近一年使用:0次
名校
解题方法
5 . 为了解全市居民月用水量,随机抽取了1000户居民进行调查,发现他们的月用水量都在
之间,进行等距离分组后,如下左图是分成6组,右图是分成12组,分别画出频率分布直方图如下图所示:
![](https://img.xkw.com/dksih/QBM/2021/7/9/2760680264638464/2762764852658176/STEM/3ba661b0bcfb4ce898d80e1f3821e738.png?resizew=578)
则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94376540b0851bbea24c6a043f5eb7cd.png)
![](https://img.xkw.com/dksih/QBM/2021/7/9/2760680264638464/2762764852658176/STEM/3ba661b0bcfb4ce898d80e1f3821e738.png?resizew=578)
则下列说法正确的是( )
A.从左图中知:抽取的月用水量在![]() |
B.从左图中知:月用水量的90°分位数为![]() |
C.由左图估计全市居民月用水量的平均值为![]() |
D.左图中:组数少,组距大,容易看出数据整体的分布特点;右图中:组数多,组距小,不容易看出总体数据的分布特点 |
您最近一年使用:0次