名校
1 . 问题探究:(1)如图1是古希腊数学家欧几里得所著的《几何原本》第1卷命题9:“平分一个已知角.”
即:作一个已知角的平分线.
欧几里得在《几何原本》中给出的角平分线作图法:在
和
上分别取点C和D,使得
,连接
,以
为边作等边
,则
就是
的平分线.
请证明
平分
;
类比迁移:
(2)小明根据以上信息研究发现:
不一定必须是等边三角形,只需
即可.他查阅资料:我国古代已经用角尺平分任意角.做法如下:如图2,在
的边
,
上分别取
,移动角尺,使角尺两边相同刻度分别与点M,N重合,则过角尺顶点C的射线
是
的平分线,请说明此做法的理论依据是______;
拓展实践:
(3)小明将研究应用于实践.如图3,校园的两条小路
和
,汇聚形成了一个岔路口A,现在学校要在两条小路之间安装一盏路灯E,使得路灯照亮两条小路(两条小路一样亮),并且路灯E到岔路口A的距离和休息椅D到岔路口A的距离相等.试问路灯应该安装在哪个位置?请在对应的示意图4中画出路灯E的位置,并说明图中所画各组线段的数量关系.
即:作一个已知角的平分线.
欧几里得在《几何原本》中给出的角平分线作图法:在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33cbad6599796efc1c177ae9349feda9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25207c30e89c36f3805068febe40e50c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
请证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
类比迁移:
(2)小明根据以上信息研究发现:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d631f45bc652539853f236952afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686171942bd7698035016c732db43b63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2032fccdf9ab12429aae024d67b19d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
拓展实践:
(3)小明将研究应用于实践.如图3,校园的两条小路
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
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2 . 综合与实践
【课本再现】在一次课题学习活动中,老师提出如下问题:如图
,四边形
是正方形,点
上边
的中点,
,且
交正方形外角平分线
于点
.请你探究
与
存在怎样的数量关系,并证明你的结论.
经过探究,小明得出结论是
,而要证明结论
,就需要证明
和
所在的两个三角形全等,但
和
显然不全等(一个是直角三角形一个是钝角三角形)考虑到点
是
的中点,小明想到的方法是如图
,取
的中点
,连接
,证明
,从而得到
.
的条件可以为( )
A.
B.
C.
D.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eaff0dae15a94c9f2865c660ea44ce5f.png)
【类比迁移】
(2)如图3,若把条件“点
上边
的中点”改为“点
上边
的任意一点”,其余条件不变,
是否仍然成立
若成立,请写出证明过程,若不成立,请说明理由.
【拓展应用】
(3)已知,四边形
是正方形,点
是直线
上一动点,
,且
交正方形外角平分线
于点
,若
,
,则
长为______.
【课本再现】在一次课题学习活动中,老师提出如下问题:如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b2d7e4f890104bf0d65c76a4eb24f29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0215e13a9fb5574d5194aeb9507a98aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8120f2eeb724c756b5f84a14c6df527.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0215e13a9fb5574d5194aeb9507a98aa.png)
经过探究,小明得出结论是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5687e49fe4b778c07f1ebe899a9f291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5687e49fe4b778c07f1ebe899a9f291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0215e13a9fb5574d5194aeb9507a98aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35e5a933a2a0ff3a28009cc989293ff5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f30cb81835298cb612a828f355060a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13017a6301e3b1264e082293fdf78bf8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5687e49fe4b778c07f1ebe899a9f291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13017a6301e3b1264e082293fdf78bf8.png)
A.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ef21f6c326b310efdc1bc2f377b2fc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9730d8c39620a403e38171c723d3dfea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd03960ade27c927e34ee28cb222615c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eaff0dae15a94c9f2865c660ea44ce5f.png)
【类比迁移】
(2)如图3,若把条件“点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5687e49fe4b778c07f1ebe899a9f291.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82bbee662e242611afdbdae4b8a36a7c.png)
【拓展应用】
(3)已知,四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7521601ac1fbc4a52d4fe44be9c8e88c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0215e13a9fb5574d5194aeb9507a98aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8120f2eeb724c756b5f84a14c6df527.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76d527d4795ece4a5756d1cf8dba31e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14a13c67f6211cb9aaa665822ce24c5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0215e13a9fb5574d5194aeb9507a98aa.png)
您最近一年使用:0次
3 . 已知:
,
平分
交
于点G.
,
,
,试判断
与
的位置关系,并说明理由;
(2)探索发现:如图②,
,
,当
时,
________;
(3)拓展探究:如图②,若
,
,
,则
________(请用含
,
的式子表示).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31e55e398e8520d8a36fb5a625a085b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4598486f8c5ac28b1165b76e78105979.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/962fa43e51eb6538898d2e4fe6947e8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6389d0e880a275cad0c0b55d4b3494e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cb1debd0dea321c4bf47e74db7fa7c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
(2)探索发现:如图②,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b6745ff962c80a79042045d72831fd4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74a7f2699f32d766e61f58a385aba1e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a11029ca6b4b9e7f777af0280cf163c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8c11be0f74427d153f2370545815fe8.png)
(3)拓展探究:如图②,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a11029ca6b4b9e7f777af0280cf163c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fab899de87d74b0b6a37befbb6f9f1f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e1128bc211fd9d44a3ecfc225e8c8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8c11be0f74427d153f2370545815fe8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
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4 . 综合与探究
如图,已知,
中,
,点D为
边上一点,连接
,将
沿直线
折叠,得到
,作
平分
交
于F.
【尝试发现】
(1)①若
,则
_______.
②若
,则
_______.
③若
,则
_______.(用含
的式子表示);
【简单应用】
(2)如图1,若
,
,求证:
;
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/16/cdfcdabd-f1f4-40f2-bd63-7131ea5bb09e.jpg?resizew=178)
【拓展延伸】
(3)如图2,若
,过点F作
的垂线交
延长线于点G,在
延长线上取点H,使
,
,试探究
,
,
三条线段之间的数量关系并证明.
如图,已知,
![](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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6344778ed1e75c1a99e2268468081867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
【尝试发现】
(1)①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aaac9788032f30d0a48efdac19f1244.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad75bdd17013af544fc97ab1dcecb873.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68696c2e42bb2cda67d3f6ed95ef973f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad75bdd17013af544fc97ab1dcecb873.png)
③若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e84d78261b991d43598f1497125376b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad75bdd17013af544fc97ab1dcecb873.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
【简单应用】
(2)如图1,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/617d321a9e88d1001fba9283c89b99b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2a4e396e52ca76229947cd997ac7c77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764cd17141471d3d84035367759e7dc6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/16/cdfcdabd-f1f4-40f2-bd63-7131ea5bb09e.jpg?resizew=178)
【拓展延伸】
(3)如图2,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27f39dacbcf8ca8364b47ac277beec70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5285138d08a82065c4a90cc5a9a8864.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/689795b69581843f657a877a5611da51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce8f887360a533f0a25b0b34fb11f0a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42887d9bf31c1dd99f13c39e63c9ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0e57a13c665af88f326c9890072bf73.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/16/cb49d746-7a4f-48e7-8c28-de2d557cc016.jpg?resizew=148)
您最近一年使用:0次
名校
5 . 综合与实践
正方形(square)是我们熟悉的几何图形,它的四条边都相等,四个角都是直角.因此,正方形既是矩形,又是菱形.它既有矩形的性质,又有菱形的性质.
条件一:正方形
、正方形
,点
落在
上,连接
、
.
条件二:连接
,取
的中点
,连接
.
根据以上条件,证明:
;
(2)【深入探究】如图2
在(1)中的正方形
、正方形
,
是
的中点,连接
,若将正方形
绕着点
旋转至点
落在
的延长线上,连接
,证明:
;
(3)【拓展应用】
在(2)中
是
的中点的条件不变,继续将正方形
绕着点
旋转,如图3,连接
交
于点
,连接
,若点
为
的中点,
的面积为2,求线段
的长.
正方形(square)是我们熟悉的几何图形,它的四条边都相等,四个角都是直角.因此,正方形既是矩形,又是菱形.它既有矩形的性质,又有菱形的性质.
条件一:正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1f13007c6d134c50004c62dc240707.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
条件二:连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6655e2fa64a32cd12fe0279afd65d73.png)
根据以上条件,证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19d8cd4452fb526c1ff4255d653d31df.png)
(2)【深入探究】如图2
在(1)中的正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1f13007c6d134c50004c62dc240707.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6655e2fa64a32cd12fe0279afd65d73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1f13007c6d134c50004c62dc240707.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42887d9bf31c1dd99f13c39e63c9ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdf9cef313e54fceed486d77948e18c4.png)
(3)【拓展应用】
在(2)中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1f13007c6d134c50004c62dc240707.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7e4fa04825ac7d071968056322d88be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abf80148409afb32ced0b4f59f1ba709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c768dedaea22607617398ce28a02dd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
您最近一年使用:0次
6 . 综合与实践
利用正方形纸片的折叠开展数学活动,探究体会在正方形折叠过程中,图形与线段的变化及其蕴含的数学思想方法.
如图①,E 为正方形
的
边上的一个动点,
,将正方形
对折,使点
与 点
重合,点
与 点
重合,折痕为
.
(1)将正方形
展平后沿过点
的直线
折叠,使点
的对应点
落在
上,折痕为
, 连接
, 如图②,请根据以上条件填空.
①点
在以点
为圆心, 的长为半径的圆上(填线段);
②
的长为 ;
拓展延伸
(2)当
时,正方形
沿过点
的直线
(不过点
)折叠后,点
的对应点
落在正方形
的内部或边上.
① 求
面积的最大值;
② 连 接
,
为
的中点,点
在
上,连接
求
的最小值.
利用正方形纸片的折叠开展数学活动,探究体会在正方形折叠过程中,图形与线段的变化及其蕴含的数学思想方法.
如图①,E 为正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/377f5c10cf527c87ab06bff61384f7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.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/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa29fe6cd9eb51c184f6299d437375cb.png)
(1)将正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6b41d4070854edfaa24071137b314cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3953cec61ac602ce5eb59b7912352179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa29fe6cd9eb51c184f6299d437375cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9171484a68c84cad91e4f2233392f600.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da650ee630c36fd5ce9abb4fb826df7b.png)
①点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3953cec61ac602ce5eb59b7912352179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83f00d88b9f850dea09aa8c682b9d610.png)
拓展延伸
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b97878915ceefd7aeccb156bc318b5da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](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/3953cec61ac602ce5eb59b7912352179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
① 求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19343455668abab3ca3b05aa2cf616c2.png)
② 连 接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/943712a5e96b16cc15d775cc4687237e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f79d7939c88e9702962e5917cad290.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/943712a5e96b16cc15d775cc4687237e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5c762edb7f688b96c33eb3ada9c3da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0eaadeeb52e7729fe8d6bdd736eaa783.png)
您最近一年使用:0次
7 . 综合与实践
正方形
中,
为对角线,点P在线段
上运动,以
为边作正方形
,连接
;
[初步探究]
(1)如图1,当点P在线段
上时,
与
的数量关系是________;
与
的位置关系为________;
,
,
三者的数量关系为
.
[探索发现]
(2)当点P在线段
延长线上运动时,如图2,探究线段
,
和
三者之间数量关系,并说明理由.
[拓展延伸]
(3)如图③,连接AE,若
,
,则
的长为________.
正方形
![](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/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e678f2aa6e90ddb48c14e905f9e4688.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
[初步探究]
(1)如图1,当点P在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0627d887d8f2fba733f5f46e981cd547.png)
[探索发现]
(2)当点P在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
[拓展延伸]
(3)如图③,连接AE,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21ea52361458ce2e49ed0fe99d8e6c02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c730e95d7c76cd1232ebd242551baf40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
您最近一年使用:0次
8 . 综合与实践
探究方法:如图1,在正方形
中,已知
,
,点E、F分别在
、
上,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/15/9ad1f162-928d-4ee8-9066-9ce9e8f7e20d.png?resizew=437)
(1)如图1,把
绕点
逆时针旋转
至
,直接写出线段
、
和
之间的数量关系;
(2)方法迁移:如图2,在四边形
中,已知
,
,点E、F分别在
、
上,
,若
、
都不是直角,但满足
,(1)的结论是否仍然成立,若成立,请写出证明过程,若不成立,请说明理由;
(3)问题应用与拓展:如图1,若
,则
________;
(4)如图3,在
中,
,
,点D、E均在边
上,且
,若
,则
的长为_________.
探究方法:如图1,在正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce0d7095ddd69d6ceaf1065b1bc2c79d.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/192155e6a3aade305b76b1eb7c75e30c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/15/9ad1f162-928d-4ee8-9066-9ce9e8f7e20d.png?resizew=437)
(1)如图1,把
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bbd6f0a0412d0f43ce1f7c1d530e56e.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/49b50357a6545cae8348e3059312f520.png)
(2)方法迁移:如图2,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce0d7095ddd69d6ceaf1065b1bc2c79d.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/192155e6a3aade305b76b1eb7c75e30c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c543c3ddc3723fde6bbfca3ea3b921b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/173904239da66b7bef7cb1d997cc40ed.png)
(3)问题应用与拓展:如图1,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7887f849a2d7546b0a608b1ff40bc8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c26a46e7879436d532af3f4b6e258a81.png)
(4)如图3,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c81f43ffb636cda0a5b17f005481cc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c76805974fefbe166b90d260e822ab5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32f01c4faacedfe56f5127d6c0cc63cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
您最近一年使用:0次
9 . 【问题提出】
(1)如图①,在正方形
中,点E在
边上,连接
,
,垂足为点 G,交
于点 F.请判断
与
的数量关系,并说明理由.
【类比探究】
(2)如图②,在矩形
中,
,点E在
边上,连接
,
,垂足为点C,交
于点F.求
的值.
【拓展应用】
(3)如图③,在(2)的条件下,平移线段
,使它经过
的中点H,交
于点M,交
于点N,连接
,若
,则
的长为 .
(1)如图①,在正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/187ed13a7bd532bd39af5e5ad7493a2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
【类比探究】
(2)如图②,在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/489d8955cfbbe8c0dc783d000c0beb88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/187ed13a7bd532bd39af5e5ad7493a2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a57799d26dbd66e5f21d327787a542e3.png)
【拓展应用】
(3)如图③,在(2)的条件下,平移线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.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/b5d8e33929752b1cb4dd36ee9b98b45d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcfc1e8e336020f326b7d3ee2ad7a306.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
您最近一年使用:0次
2024-04-22更新
|
198次组卷
|
6卷引用:数学(黑龙江哈尔滨卷)-【试题猜想】2024年中考考前最后一卷
数学(黑龙江哈尔滨卷)-【试题猜想】2024年中考考前最后一卷2024 年青海省西宁市初中学考九年级调研测试(一模)数学试题(已下线)重难点05 四边形压轴类型归纳(9大题型+满分技巧+限时分层检测)-2024年中考数学【热点·重点·难点】专练(广东专用)2024年四川省内江市威远县凤翔中学中考二模考试数学试题2024年山东省聊城市高唐县九年级下中考第二次模拟数学试题2024年山东省聊城市阳谷县九年级中考二模数学试题
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10 . 【问题背景】已知:在
中,
,点D、E分别为直线BC上两动点,探究线段
、
、
三条线段之间的数量关系:
时,点D、E分别为线段
上两动点且
,猜想
、
、
三条线段之间存在的数量关系式,直接写出你的猜想__________;
【问题拓展】(2)如图2,当动点E在线段
上,动点D运动在线段
延长线上时,其它条件不变,(1)中探究的结论是否发生改变?请说明你的猜想并给予证明;
【问题迁移】(3)如图3,当
时,点D、E在边
上,
,点F在边
上,点F到
的距离是
且
,
,求
的面积.
![](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/b3182db896bc2462331796e2a6108363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a6c6e7c025362c46a64a8956761f08e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9171484a68c84cad91e4f2233392f600.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c06154cae3bf7a8ce5a1e97a7380875.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c76805974fefbe166b90d260e822ab5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3182db896bc2462331796e2a6108363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a6c6e7c025362c46a64a8956761f08e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9171484a68c84cad91e4f2233392f600.png)
【问题拓展】(2)如图2,当动点E在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/971b23e3ee827018557d6c88edd5369a.png)
【问题迁移】(3)如图3,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b57fdd2a3642716fcf5100011eb3ec88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3db6fc3f3db5ed2f517cdad4a257c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1a9c6a736e6eac98a676fa3232db5a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5101ab05fce5c1190dc22f7e7887aaa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/002767b8780fc8bf7aafc7beb2bae1e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc7f32e4c7d1fcafc3fe0dbcf08fdd2e.png)
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