1 . (1)问题背景
如图1,
中,
,
,
的平分线交直线
于
,过点
作
,交直线
于
.请探究线段
与
的数量关系.(事实上,我们可以延长
与直线
相交,通过三角形的全等等知识解决问题.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
结论:线段
与
的数量关系是 (请直接写出结论);
(2)类比探索
在(1)中,如果把
改为
的外角
的平分线,其他条件均不变(如图
,(1)中的结论还成立吗?若成立,请写出证明过程;若不成立,请说明理由;
(3)拓展延伸
在(2)中,如果
,且
,其他条件均不变(如图
,请你直接写出
与
的数量关系.
结论:
(用含n的代数式表示).
如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](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/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a45b04cc3e5adaeff6f9e01e29032803.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
结论:线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(2)类比探索
在(1)中,如果把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d786ee723231d4ca87eb9d011a378b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad217e26bd3580c35998109de14cef73.png)
(3)拓展延伸
在(2)中,如果
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6eab933fd3ed8a3a412a6f268d4cef4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8d68c94069d6f8f2f7b11fe83f7acd1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2324a65e345753fdd1db2354bfb0ee4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
结论:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c978d92edf0c4c1ef8620c17df75d35e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/15/937e0197-6e18-41b6-a0f3-7d0c678b0072.png?resizew=426)
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2 . 问题提出
在综合与实践课上,某数学研究小组提出了这样一个问题:如图1,在边长为4的正方形
的中心作直角
,
的两边分别与正方形
的边
,
交于点E,F(点E与点B,C不重合),将
绕点O旋转.在旋转过程中,四边形
的面积会发生变化吗?
爱思考的浩浩和小航分别探究出了如下两种解题思路.
浩浩:如图a,充分利用正方形对角线垂直、相等且互相平分等性质,证明了
,则
,
.这样,就实现了四边形
的面积向
面积的转化.
小航:如图b,考虑到正方形对角线的特征,过点O分别作
于点G,
于点H,证明
,从而将四边形
的面积转化成了小正方形
的面积.
__________;
__________.
类比探究
(2)①如图⒉,在矩形
中,
,
,O是边
的中点,
,点E在
上,点F在
上,则
__________.
②如图3,将问题中的正方形
改为菱形
,且
,当
时,其他条件不变,四边形
的面积还是一个定值吗?若是,请求出四边形
的面积;若不是,请说明理由.
拓展延伸
(3)如图4,在四边形
中,
,
,
,
,
是
的平分线,求四边形
的面积.
在综合与实践课上,某数学研究小组提出了这样一个问题:如图1,在边长为4的正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b2557547eecdc826b8282058802d217.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b2557547eecdc826b8282058802d217.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b2557547eecdc826b8282058802d217.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
爱思考的浩浩和小航分别探究出了如下两种解题思路.
浩浩:如图a,充分利用正方形对角线垂直、相等且互相平分等性质,证明了
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8e9b8559813d320d0439aeb6a7fb32b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29469ffc253990fb7036224c0807eabc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11cf9c64341fe7583043e5e721a9f4c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4807ca16360c0cca436e59d4be98f626.png)
小航:如图b,考虑到正方形对角线的特征,过点O分别作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbdaf6769ca790186718cc60c7b89ba6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27acaeba896dd1a4a221151ffa464848.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18f651cafe4e7eabefc7d9db3364a46e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/576f3737faa25501719f13e7495d7ef3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8678190eb56dda0061c60fe08bc2a86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a12ffa9b9913fb53f8f50a420df7373.png)
类比探究
(2)①如图⒉,在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/267ace52b64e1e7dfc5211e033255b7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/319ff9f648fedec284a11a9761cb6183.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/f273e22d58841c1a850d4b96cebbcaf9.png)
②如图3,将问题中的正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e901c430af74f7bbce43364bd4f2e47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee480d748f36c1b43e941384dd41f13e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e689223dbda856ab0898b0010ffb86a.png)
拓展延伸
(3)如图4,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b8b709a173120436dac669c74b927d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16ed75e65e7374c38ffb1f75259a8beb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b0382c28547d3834ca71f3f0677695.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/411b38a18046fea8e9fab1f9f9b80a5f.png)
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3 . 动手操作
利用旋转开展数学活动,探究图形变换中蕴含的数学思想方法.
如图1,将等腰直角三角形
的边
绕点B顺时针旋转
得到线段
,
,
,连接
,过点
做
交CB延长线于点H.
(1)在图1中:易知
,则
;
如图2,若
为任意直角三角形,
、
、
、
分别用a、b、c表示.
边绕点B顺时针旋转
,得到
,过点
作
,交BC延长线于点
.
(2)在图2中:
的面积为 ;
拓展延伸
(3)如图3,在
中,
,
,
,
,
,连接
.
①求
的面积;
②在
中,在BC边的高上找一点D,使
的值最小,求AD的长和
的最小值.
利用旋转开展数学活动,探究图形变换中蕴含的数学思想方法.
如图1,将等腰直角三角形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e663220a66eff19da6a71e46b397db2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca036d049f5205cf04cb1b9c5cd03f97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eb97aff0960e2640314888a38e7169c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7c314398e26ffc7164b82946eeb4273.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c19a6e91938fd1e4de242717fd5108c7.png)
(1)在图1中:易知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ef29b2ad2766db967bd83be7980055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcd742b5ad5b1d0bf8baeaf98882c7a6.png)
如图2,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e663220a66eff19da6a71e46b397db2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7c314398e26ffc7164b82946eeb4273.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/177cb2899e7a6464fa3786e9183ac56d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d955d197e2ecbfe724570663efcf2a2d.png)
(2)在图2中:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2df93bd15f25096c510b589aad0dfc1.png)
拓展延伸
(3)如图3,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2212db470de13d686a921bc7da751f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc34db5860990e51ba31edc8cdd077c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b939af5ba06e279cce39396aaf0fae06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae6457ac54bcdcf5d67f4271127b1555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eb97aff0960e2640314888a38e7169c.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2df93bd15f25096c510b589aad0dfc1.png)
②在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e055d012a9b8f2d3274a397270c51aa8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e055d012a9b8f2d3274a397270c51aa8.png)
您最近一年使用:0次
4 . 综合与实践
在综合与实践课上,老师让同学们以“三角形全等“为主题开展数学活动:
【问题情景】如图
,已知两条线段和一个角,以长的线段为已知角的邻边,画一个三角形,把你画的三角形与其他同学画的三角形进行比较,所画的三角形都全等吗?此时,符合条件的角形有多少种?
(1)【操作发现】如图
,善思组通过作图发现,此时
即“边边角”对应相等
的两个三角形______ 全等
填“一定”或“不一定”
.
(2)【探究证明】钻研组受善思组的启发,提出并解决了图2中以下问题:
已知:如图2,在
和
中,
,
,
.求证:
.
请阅读并补全证明
证明:在
上取一点
,使
.
,
.
又
.
而
.
.
,
.
又
.
.
.
(3)【拓展应用】创新小组在此基础上进行了深入思考,把
变为等腰三角形,且
,点
在射线
上,点
在
的延长线上,
,连接
,
与
边所在的直线交于点
请帮忙解决以下两个问题:
当点
在线段
上时,如图
所示,求证:
.
过点
作
交直线
于点
,若
,
,则
______.
在综合与实践课上,老师让同学们以“三角形全等“为主题开展数学活动:
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/10/cb4c0cf6-5fcc-44ab-9f87-73e658dc1eb1.png?resizew=487)
【问题情景】如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
(1)【操作发现】如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd995178601c2ad7b40f973d268c7bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd995178601c2ad7b40f973d268c7bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
(2)【探究证明】钻研组受善思组的启发,提出并解决了图2中以下问题:
已知:如图2,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79de59390a7059cfdea1f42ce1ffac70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c244edbf77fbb8e9c017515e370c5c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15d91c2c71301cbb983e317b83d23b30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a510a3eb906b3ef0760b0d1723d11ae.png)
请阅读并补全证明
证明:在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fe3865df6e6ec4d3bf6bc66079e02c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/caf9a4c4eea45afde2554ba29cdc6b0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/223b398c174d5b66d3bb0d615b775ee0.png)
又
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cecc96eb96eab336876d8740287bc00c.png)
而
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f978fb894ebfe2bc4c1cfee41291724.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1abd0b9aee17d467e09191bda2bd54fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d42dbc0dcc1a5fc803bef4a11b2b1b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cba2b442c0f244efea6cc92a2c14c635.png)
又
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16f3d198e76391779fa3badc848c8ac8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db67a01ab28026f84da4b73d8f09ae48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/042073161bfc6f2ce835725cdf81c817.png)
(3)【拓展应用】创新小组在此基础上进行了深入思考,把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.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/421291381be28da4bd16560fd383b4a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af00a2603bb1c492527537d60949c76c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e1c9ae241fd78126274c65e17990c88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46ce838f38419e8781d63b3417cac5e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c650fe55b7603f106c53ca2423451c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d260eccf8d16e9ec44722fb55df12b55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07160f14b3b453bebb64cb2bf96dc85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3362a45b72536c714c5107b0ae94f1c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e246bc4a4d491259fabc9c7497d6242.png)
您最近一年使用:0次
5 . 【实践操作】
在矩形
中,
,现将纸片折叠,点D的对应点记为点P,折痕为
(点E、F为折痕与矩形
边的交点),再将纸片还原,若点P落在矩形
的边
上(如图①所示),当点P与点A重合时,
;当E与点A重合时,
;
【初步思考】
当点E在
上,点F在
上时(如图②所示),求证:四边形
为菱形;
【深入探究】
当点P落在矩形
的内部(如图③所示),且点E、F分别在
边上时,则
的最小值为 ;
【拓展延伸】
若点F与点C重合(如图④所示),点E在
上,线段
与线段
交于点M,
,则线段
的长为 .
在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02fcd95e6fd6ea1ec7cc880856846f7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/617d321a9e88d1001fba9283c89b99b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6618b4d41917e695da2356c016242ba4.png)
【初步思考】
当点E在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/213a169e7fd26fcd32fb159bee2a3f91.png)
【深入探究】
当点P落在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed86911acfc988cd24508976ca8afc94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
【拓展延伸】
若点F与点C重合(如图④所示),点E在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fb26d84907c923278ac4626a9d58947.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0579a9f5bb951e54bc82a0a6d2c36a1b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
您最近一年使用:0次
6 . (1)【探究发现】如图①,已知矩形
的对角线
的垂直平分线与边
,
分别交于点E,F.求证:四边形
是菱形;
(2)【类比应用】如图②,直线
分别交矩形
的边
,
于点E ,F,将矩形
沿
翻折,使点C的对称点与点A重合, 点D的对称点为
,若
,
,求
的长;
(3)【拓展延伸】如图③,直线
分别交平行四边形
的边
,
于点E ,F,将平行四边形
沿
翻折,使点C的对称点与点A重合,点D的对称点为
,若
,
,
,求
的长.
![](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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9766e5eb6796dafc5ffe212afdfc43c0.png)
(2)【类比应用】如图②,直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5b3bd5e6bc2a0a277d279bb01af9584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/495ad8b56428d2bce422618dff03b97a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7a9076e0157e5d5ed363ec768f7ae96.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
(3)【拓展延伸】如图③,直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5b3bd5e6bc2a0a277d279bb01af9584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080ca48cd27d4bf9d9ef084b558fc17a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b173ac8cc4ac4f1c9e1daaa605fbb27.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
您最近一年使用:0次
名校
7 . 阅读理解,自主探究:
“一线三垂直”模型是“一线三等角”模型的特殊情况,即三个等角角度为
,于是有三组边相互垂直.所以称为“一线三垂直模型”.当模型中有一组对应边长相等时,则模型中必定存在全等三角形.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/8/388962d5-e0d8-40ae-9a22-748d4175408b.png?resizew=351)
(1)问题解决:如图1,在等腰直角
中,
,
,过点C作直线
,
于D,
于E,求证:
;
(2)问题探究:如图2,在等腰直角
中,
,
,过点C作直线
,
于D,
于E,
,求
的长;
(3)拓展延伸:在平面直角坐标系中,
,
为等腰直角三角形,
,
,求B点坐标.
“一线三垂直”模型是“一线三等角”模型的特殊情况,即三个等角角度为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/8/388962d5-e0d8-40ae-9a22-748d4175408b.png?resizew=351)
(1)问题解决:如图1,在等腰直角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/777b2fbc01cfc26cde436f625a5b7cb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/526108bb5ea7ed33052b0eb47072bc34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c1c122603b60b6f1a1334ddb56c3fb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d744f121ee858da2db4a516ea3f54cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e57c76abca2467af86f45da0fec08cb.png)
(2)问题探究:如图2,在等腰直角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/777b2fbc01cfc26cde436f625a5b7cb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/526108bb5ea7ed33052b0eb47072bc34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ccd5c41c921836b50f8e18abfdc5df3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31b2cc1d0bfd22c88286880b9da1f6f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a48a908fd75d2684e2e848897b45bfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
(3)拓展延伸:在平面直角坐标系中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa508c303911aff49a9697974a0ef358.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/777b2fbc01cfc26cde436f625a5b7cb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/526108bb5ea7ed33052b0eb47072bc34.png)
您最近一年使用:0次
2023-04-07更新
|
296次组卷
|
3卷引用:江苏省盐城市滨海县第一初级中学教育集团2022-2023学年八年级上学期第二次练习数学试题
名校
8 . 在等腰
中,
.
问题背景如图1,
,点
在
上,且
,连接
交于
,请你完成作图,并直接写出
的度数.
迁移应用如图2,
,点
在
内,满足
,延长
至
使得
,作
,请你完成作图,并探究线段
之间的数量关系.
联系拓展如图3,
,若点
满足
,直接写出点
到直线
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99f18c9f77f00d71b8ebe6e721857a59.png)
问题背景如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97cf714ffb3fd5917a76b191640b55fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6670479a0083dd2dfd5ad55b47b1ab6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/887721a843b2dc8e947cc42d09868e33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdc9f4a99b567a6ee4be3943beeddca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53135ab7d67cf2515321ec72f55e0905.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfc6f50c441d803f3b5ab60acc15a30d.png)
迁移应用如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97cf714ffb3fd5917a76b191640b55fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa251b3038b2332b7df3bfafa0768d6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d86bdca15922c7896ffe4de3a06bc21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a92cbe1854e9158dde43d10f915799d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/736a7635c944aa825cc9b8bac3b0d6d8.png)
联系拓展如图3,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b117fa14824962908f718148635f9b6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86ab768b7133766c2092ec51f7688d5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/26/5281d0ef-8e4b-4f2c-8adf-c43740c7615d.png?resizew=376)
您最近一年使用:0次
9 . 【阅读思考】
在平面直角坐标系
中,点
的坐标分别
,
且
,点
是平面内一点,连接
.定义:在上述条件下,若
,则称点
是
的智慧点,记作
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/20/d4dd91c7-f6d2-4c76-93bf-fecf8c20babf.png?resizew=309)
【初步探究】
(1)如图1,
分别在
轴、
轴的正半轴上.
①若
,
,
,求证:点
是
的智慧点;
②若
,用含
的式子表示点
的坐标.(直接写出答案)
【理解应用】
(2)若
,
,且
,求
的值.
【拓展迁移】
(3)若
,
,点
,且
,求点
的坐标.
在平面直角坐标系
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae6f48b9a53c0155a692509cf31f7e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d345e61f024bf07329cd27dc0bfadcf2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64ba819698caf577d2d2d4c598c0f50a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9eae9ba258299eb489b490594397e23c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba85e0d27c9dfb7be464ecf135f3e094.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/931813dbb01614b3de5d6f416203dabb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae6f48b9a53c0155a692509cf31f7e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/372a8b74554296a4d12fcf28165c1c3c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/20/d4dd91c7-f6d2-4c76-93bf-fecf8c20babf.png?resizew=309)
【初步探究】
(1)如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae6f48b9a53c0155a692509cf31f7e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa4c355f11471a38f5583a434a1ddeb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03837b3769eda7f0d3804cc5ad4a6d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18c777c09623824075b49fd91f8a5b7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae6f48b9a53c0155a692509cf31f7e6.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/372a8b74554296a4d12fcf28165c1c3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62ff2912fd8d93b6e692936d95b727c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
【理解应用】
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/372a8b74554296a4d12fcf28165c1c3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c3361f3a17a971558914bb4a5b88a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d12fefd3a33b28372260f1ba5d946efb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
【拓展迁移】
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b108ab31cc093f03cf48ad65429889e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a3c442579603164f3fc19458677d307.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25c43f704b5d150cb4e29e9796a07d80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0b442751d96abcc200750fb2bcdff93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
您最近一年使用:0次
10 . 在
中,
于点D,点P为射线
上任一点(点B除外),连接
,将线段
绕点P顺时针方向旋转α,
,得到
,连接
.
,且
时,
与
的数量关系是 ,
与
的位置关系是 .
(2)【猜想证明】如图2,当
,且
时,(1)中的结论是否成立?若成立,请予以证明;若不成立,请说明理由.(请选择图2,图3中的一种情况予以证明或说理)
(3)【拓展探究】在(2)的条件下,若
,
,请直接写出
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70734a8e672376bb0bd1522e229f86a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afbc28ba86213e215af01cb50e95aaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc5adb5eb60ae4435a12d93854066298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b6e4a2df58a236c20df5df0d29a466c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
(2)【猜想证明】如图2,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b6e4a2df58a236c20df5df0d29a466c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
(3)【拓展探究】在(2)的条件下,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cedd51383f8f047f565191b128cec637.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/574dc284fb9e74d65cf0c79a978d65de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
您最近一年使用:0次