名校
1 . 如图,已知
,
,
,且点
,
、
、
在同一条直线上.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd81adb13f5a7550b0f94f770900a613.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a510a3eb906b3ef0760b0d1723d11ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f805768a5ffaf8bdfa4bc3b680aafdc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.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/79d9cc37ac19a35e2bf17921443dbb81.png)
您最近一年使用:0次
7日内更新
|
174次组卷
|
2卷引用:2024年陕西省西安市陕西师范大学附属中学中考七模数学试题
2 . 【模型建构】
如图1,点O在直线
上,射线
,
位于直线
两侧,若
,则称
,
是关于直线
的对称角
当射线
,
位于
同侧且
时,可以通过作对顶角构造出对称角,可以反向延长射线
,得到
(如图2),或者反向延长射线
,则
(如图3).
【模型应用】
(1)小明受到模型启发,运用两种方法构造出对称角解决了下面问题:
如图4,点C,D在
上,点E,F在直线
外,连接
,
,
,
,若
,
,求
的度数.
方法一:延长
至H,使
,连接
,
方法二:延长
至H,使
,连接
,
请你依照小明的解题思路,任选一种方法,写出证明过程;
(2)小明又尝试将(1)中问题进行变式提出了新问题,请你应用“对称角”模型构造全等三角形或者按照自己的解题思路解答.
如图5,在
中,
,点D是
的中点,点E,F分别在
,
上,
,
,猜想
,
,
之间的数量关系,并说明理由.
【学以致用】
(3)如图6,在四边形
中,
,
,
,
相较于点E,且
,若
,
,求
的长.
如图1,点O在直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5b69d40b75d582c4b8ffa2369af1d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d57899ad4774aed9ccc7bd23db72153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
当射线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba02910a01689f636c71116e96dfdf33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/683c590673eece14fea3319c4fd5eb55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e50ce9ef89a466df68124a1dccff5663.png)
【模型应用】
(1)小明受到模型启发,运用两种方法构造出对称角解决了下面问题:
如图4,点C,D在
![](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/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84afb69b68118ab366b661818abf8c19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/100fc25ea045c174e66e48d4f0c66a2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/beb3748300134501953d6b1c3a905026.png)
方法一:延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43e2aa7d6feda1eddcd1421fb1b1fbca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6655e2fa64a32cd12fe0279afd65d73.png)
方法二:延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bab17635a999236e8d2e35017a208d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da9bc26abb83370469132b708f87123a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6655e2fa64a32cd12fe0279afd65d73.png)
请你依照小明的解题思路,任选一种方法,写出证明过程;
(2)小明又尝试将(1)中问题进行变式提出了新问题,请你应用“对称角”模型构造全等三角形或者按照自己的解题思路解答.
如图5,在
![](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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec8dc90d8e4cddcb1b21c34732cd18cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93bb64de3eb4fb1f8f657a40c147ae02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
【学以致用】
(3)如图6,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9f438c6b7f3527959227eab7043e166.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d875f0d9448d025bb6dfad47dd55fad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecf7679c8b4b1e442ce4286d4b0e9c32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19faa41278c9f5013f17b201a75db964.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
您最近一年使用:0次
3 . 初中几何学习一般路径为:线——三角形——四边形——多边形,线的学习依据位置关系又分为相交线、平行线.三角形、四边形的学习都是由一般到特殊,从一般三角形、四边形到特殊三角形、四边形,且研究了其特殊性质.学习过程中,同学们发现两个全等的特殊三角形即拼成一个特殊四边形.特殊三角形与特殊四边形之间有很多联系.因此在探究特殊四边形中一些线段之间关系时往往和特殊三角形结合起来.下面是数学翱翔社的同学在课后探究特殊三角形与特殊四边形一些重要线段之间关系的过程:
探究发现
如图1,在
中,
,
,点D在
边的延长线上,以
为边作正方形
(与
在
边同侧),连接
,点G为
的中点,连接
.发现
,
.
证明思路如下:
延长
交
于点H,连接
.证明
,点G为
的中点,即可证明结论.
依据提供思路写出规范的推理过程.
类比猜想
(2)等边三角形与有一个角为
的菱形中的特殊线段之间的关系.
如图2,在等边三角形
中,点D在
边的延长线上,以
为边作菱形
,
(与
在
边同侧),连接
,点G为
的中点,连接
.猜想
的数量关系以及位置关系,并说明理由.
拓展延伸
(3)一般等腰三角形与有一个角和等腰三角形顶角度数相等的菱形中特殊线段之间的关系.
如图3,当
为等腰三角形,
,四边形
为菱形,且
时,其他条件不变,请直接写出
的数量关系.
探究发现
如图1,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/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/779c26a41987ef67c2f09812c4f15ac4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0213c5787a5a6b38d11bceca5567f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0213c5787a5a6b38d11bceca5567f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9848ea064400aefb91dd3e5a066e760.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/deaf896af5f5a09da3e50a7964d26ba1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e2f06a21c1b60255379fd27425b6e1b.png)
证明思路如下:
延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d87448e09eaa816e50ae92d111d5ded6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54977f2005907cb28a0289f0ea4b1d12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79448c0b5a49eb055bd70c0c4db2fceb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3b37020a1975e5133c3971645f2849.png)
依据提供思路写出规范的推理过程.
类比猜想
(2)等边三角形与有一个角为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3ad1b0a76a887783392268ae203ad22.png)
如图2,在等边三角形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/787ac5e13622afab5e9f8603afe42356.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ffb98f1e3c1317c0db403d3af04bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/779c26a41987ef67c2f09812c4f15ac4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5dccf06184656f261d47dee4155ee895.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0213c5787a5a6b38d11bceca5567f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0213c5787a5a6b38d11bceca5567f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9848ea064400aefb91dd3e5a066e760.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9848ea064400aefb91dd3e5a066e760.png)
拓展延伸
(3)一般等腰三角形与有一个角和等腰三角形顶角度数相等的菱形中特殊线段之间的关系.
如图3,当
![](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/779c26a41987ef67c2f09812c4f15ac4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21953d4d150833556b71babaf4bd6a73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9848ea064400aefb91dd3e5a066e760.png)
您最近一年使用:0次
4 . 【教材呈现】
中,
是
上的一点,
经过旋转后得到
,
①旋转中心是点______;旋转角最少是______度.
②爱动脑筋的小明,在
边上取点
,连接
,使得
,他发现:
,他的发现正确吗?请你判断并说明理由.
【结论应用】
(2)①图1中,若正方形
的边长为
,则
的周长为______(用含有
的式子表示).
②如图2,在四边形
中,
,
,
,
是
的中点,且
,则
的长
______.
【类比迁移】
(3)如图3,在菱形
中,
,在线段
上选一点
(不与点
重合),沿
折叠,得到
,在线段
上取点
,沿
折叠,使得点
与点
重合,连接
,分别交线段
于点
,若
,
,求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/441dec590b47adc3678a291a3ec89a4a.png)
①旋转中心是点______;旋转角最少是______度.
②爱动脑筋的小明,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7635680fefd93dd95274c933b5289c59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/851b6466fc810946d7f12926e35000d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0638ba7cde29c89dbc8f8313ef4c044d.png)
【结论应用】
(2)①图1中,若正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3f3197779e26c71a1b633b279613969.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
②如图2,在四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a403690bc9ebcdc611a818061d85ffeb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60d9142db4dd2ef151bf3d4a63afb61e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f8e60a89b6a39d8dd53265f951dee7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a1af32e267e35ef79bcb8df5d169283.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6706fe00b4e231e62d9ecbec567d526b.png)
【类比迁移】
(3)如图3,在菱形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80934ff67b4ceeaa13b00c029db565dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72b886208c6c2df19b984f2631e1c996.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6ede9761b5b90f8dc137708e1ee90f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1aaf5c27cab84ebf216ac14252083e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e83fd42df335c85bf92b7961b9851977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7978151ee28b5d0b797786526d303d21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1e4ac6afae99c319e0fdc374f7e08ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e42887d9bf31c1dd99f13c39e63c9ab9.png)
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5 . 如图,在
和
中,
,
,
,点
在线段
上,
,
交于点
,连结
.
平分
.
(2)若
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8abfdaab699cfe51bb9678110ad6aee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d212c1709b8e72a055cf1b5381ef64.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/1a6c6e7c025362c46a64a8956761f08e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1a9c6a736e6eac98a676fa3232db5a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6b41d4070854edfaa24071137b314cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1a9c6a736e6eac98a676fa3232db5a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e1da12b51149bf0b494d8124e20489e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34d35f17327d19a82e87b792dad37b52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
您最近一年使用:0次
7日内更新
|
91次组卷
|
2卷引用:2024年 浙江省温州市浙师大协同体九年级下学期数学诊断试题
6 . 综合与实践
莹莹复习教材时,提前准备了一个等腰三角形纸片
,如图,
,
.为了找到重心,以便像教材上那样稳稳用笔尖顶起,她先把点B与点C重叠对折,得折痕
,展开后,她把点B与点A重叠对折,得折痕
,再展开后连接
,交折痕
于点O,则点O就是
的重心.
(1)初步观察:连接
,则
与
的数量关系是:________;
(2)初步探究:请帮助莹莹求出
的面积;
(3)猜想验证:莹莹通过测量惊奇地发现
,
.她的发现正确吗?请说明理由.
莹莹复习教材时,提前准备了一个等腰三角形纸片
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c8817091d0f4b7d7ac6df560cb63c68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07160f14b3b453bebb64cb2bf96dc85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
如图,用铅笔可以支起一张均匀的三角形卡片.你知道怎样确定这个点的位置吗?![]() ![]() ![]() |
![](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/274cf35acb4a1748d15c39d15a9bea7b.png)
(2)初步探究:请帮助莹莹求出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bbf9680f74a9ac5d934304654ce2771.png)
(3)猜想验证:莹莹通过测量惊奇地发现
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/321231b7c9c2902f953d47f0137bb823.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11995c96da35c9a923c86385e5a572ee.png)
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名校
7 . 如图1,在正方形
中,
,O是边
的中点,E是正方形内一动点,且
,连接
,将线段
绕点D逆时针旋转
得
,连接
.
;
(2)求
的面积的最小值;
(3)如图2,若A,E,O三点共线,求点 F到直线
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04725e51b4870658f74de79403e3898f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93af9774200946261f0ccba3e6eeba9d.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/c02b54dc6b3e1bb6544f47d4c8743fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/464dcd1cc7132f27de154962ed83730b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8ce1475f537b4ad21775bfaa16daa0c.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5df7626240940eb340420a605e95aeee.png)
(3)如图2,若A,E,O三点共线,求点 F到直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
您最近一年使用:0次
8 . 如图,矩形
中,
是
边上一动点,连接
,把线段
绕点
顺时针旋转
得到线段
.
与点
重合时,
______度.
(2)在点
从点
向点
运动的过程中,猜想点
所走过的路程与
的长有什么关系?请说明理由.
(3)在点
从点
向点
运动的过程中,当
取得最小值时停止,求点
所走过的路程长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/703976694265b1106f6e3772c849f27f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/681812232364565c95c1c0c967af3f13.png)
(2)在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.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/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
(3)在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.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/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
您最近一年使用:0次
9 . 如图,在菱形
中,
,点
分别是边
和对角线
上的动点,且
,连接
相交于点M,点P是
边上的一个动点,连接
,则
的最小值是_______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f862386eab3bd34c931de45232e2e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a373959bb9026f8a09845c0b828bf82.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/f805768a5ffaf8bdfa4bc3b680aafdc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08fbd0f56b46687f9635d4a3c3f7521a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ec596836574eb4b866205420c3a5e18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edbde97674526a51bc36ff4b91a07712.png)
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10 . 如图,E,F分别是正方形的边
,
上的点,连接
,
,
,
,则下列结论中一定成立的是( ).
![](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/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/192155e6a3aade305b76b1eb7c75e30c.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次