如图,在平行四边形
中,E,F分别为边
的中点,
是对角线.
是平行四边形;
(2)当
平分
时,判断四边形
是什么特殊的平行四边形,并说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdcf86f7cf381c563ad80af86feeed83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f3c15b30bd155641e548a7d8c172dd4.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/868ff1350bd72625328c85c3097cd85e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f3c15b30bd155641e548a7d8c172dd4.png)
更新时间:2024-05-13 10:46:28
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相似题推荐
解答题-证明题
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名校
【推荐1】如图,在正方形
中,点E是
的中点,连接
,过点A作
交
于点F,交
于点G.
;
(2)连接
,求证:
.
![](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/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50e44aea5bb106f75dfe580f5f95d429.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e336500b8abeabbc9b3b896a1c48c273.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bae20ce509b25695607c660bf7023fa.png)
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【推荐2】如图,在平行四边形
中,E、F分别是
、
上的点,且
.求证:
.
![](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/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e817bbd09ab01c5b3947efc2e396adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92034dd2bb9480b18709d01153467f8f.png)
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【推荐1】如图,在
中,点
、
是对角线
上两点,且
.
![](https://img.xkw.com/dksih/QBM/2019/9/5/2284117306966016/2284206652850176/STEM/6c55c3eb1ff74b37bec86825b35aafc0.png?resizew=227)
(1)求证:四边形
是平行四边形.
(2)若
.
,且
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5138a9f70d5e8b0580e30fef6eb7baef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8ce1475f537b4ad21775bfaa16daa0c.png)
![](https://img.xkw.com/dksih/QBM/2019/9/5/2284117306966016/2284206652850176/STEM/6c55c3eb1ff74b37bec86825b35aafc0.png?resizew=227)
(1)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c87e1fe20bb0e8292e993657e14bc79a.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc1578d25693ec1b0e407e6376c4f7f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b27e47690ed332c573186992b6d25654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d320f180419175d75eebc618cc458b39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5138a9f70d5e8b0580e30fef6eb7baef.png)
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【推荐2】如图,已知△ABC中,AC=6cm,BC=8cm,AB=10cm,动点P从点C出发,沿着△ABC的三条边逆时针走一圈回到C点,速度为2cm/s,设运动时间为t秒.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/bfd91d37-e75d-4a51-84be-2b92c33208cf.png?resizew=136)
(1)判断△ABC的形状,并求AB边上的高;
(2)t的取值是________时,△ACP为等腰三角形?
(3)另有一点Q,从点C开始,按顺时针走一圈回到C点,且速度为每秒1cm,若P、Q两点同时出发,当P、Q中有一点到达终点时,另一点也停止运动.当t为何值时,直线PQ把△ABC的周长分成相等的两部分?
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/bfd91d37-e75d-4a51-84be-2b92c33208cf.png?resizew=136)
(1)判断△ABC的形状,并求AB边上的高;
(2)t的取值是________时,△ACP为等腰三角形?
(3)另有一点Q,从点C开始,按顺时针走一圈回到C点,且速度为每秒1cm,若P、Q两点同时出发,当P、Q中有一点到达终点时,另一点也停止运动.当t为何值时,直线PQ把△ABC的周长分成相等的两部分?
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【推荐1】如图,在Rt△ABC中,∠ACB=90°,D、E分别是AB、AC的中点,连接CD,过E作EF∥DC交BC的延长线于点F.
(1)求证:四边形CDEF是平行四边形;
(2)若EF=5,求线段AB的长度.
(1)求证:四边形CDEF是平行四边形;
(2)若EF=5,求线段AB的长度.
![](https://img.xkw.com/dksih/QBM/2019/6/12/2224147330686976/2228095184961536/STEM/17089606-809d-4026-81c8-b6a0ced263ae.png?resizew=228)
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解答题-作图题
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【推荐2】如图,在
中,
分别交
,
于点E,F.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/7/a40f8a65-760d-4dce-94cb-09412ac3a74c.png?resizew=185)
(1)用尺规完成以下基本作图:过点A作
的垂线,分别交
,
于点G,H,连接
,
;(保留作图痕迹,不写作法和结论)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/7/0c7953cc-3e3a-4e7c-8fcc-d4a73037f43c.png?resizew=193)
(2)根据(1)中所作图形,小南发现四边形
是平行四边形,并给出了证明,请你补全证明过程.
证明:
∵四边形
是平行四边形,
∴
,①___________,
∴
.
∵
,
,
∴
②___________,
∴
,
∴③________________,
又∵④_____________,
∴
.
在
与
中,
,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47f8f354d764940debcc1d18d5f3dc16.png)
∴⑤_________.
又∵
,
∴四边形
是平行四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5138a9f70d5e8b0580e30fef6eb7baef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/531d6f90f144551a35d494b1fe7d2b89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/7/a40f8a65-760d-4dce-94cb-09412ac3a74c.png?resizew=185)
(1)用尺规完成以下基本作图:过点A作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.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/abf80148409afb32ced0b4f59f1ba709.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/4/7/0c7953cc-3e3a-4e7c-8fcc-d4a73037f43c.png?resizew=193)
(2)根据(1)中所作图形,小南发现四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0da738931a00698520e8a776398adc43.png)
证明:
∵四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c220eadc312101e2fb89dfe920f7b30d.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8c09052a6d3dd492f1c2f13c8afcbab.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff4744b427f036dfbc6db68c87cd5c54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/531d6f90f144551a35d494b1fe7d2b89.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/680664104cfb9812df1b795c7f6acdfc.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5019dfc6ef65950d963809e37cc3a0.png)
∴③________________,
又∵④_____________,
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6956f1f3826089236b7f568f02f638cc.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bc727c642cbc2181476b7dd8eca471e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5df7626240940eb340420a605e95aeee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35ba9b23a4300fa8fdaabb5b3aa07330.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47f8f354d764940debcc1d18d5f3dc16.png)
∴⑤_________.
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5019dfc6ef65950d963809e37cc3a0.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0da738931a00698520e8a776398adc43.png)
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真题
【推荐1】综合与实践
问题情境
在综合与实践课上,老师让同学们以“菱形纸片的剪拼”为主题开展数学活动,如图1,将一张菱形纸片ABCD(
)沿对角线AC剪开,得到
和
.
操作发现
(1)将图1中的
以A为旋转中心,逆时针方向旋转角
,使
,得到如图2所示的
,分别延长BC和
交于点E,则四边形
的状是 ;
(2)创新小组将图1中的
以A为旋转中心,按逆时针方向旋转角
,使
,得到如图3所
示的
,连接DB,
,得到四边形
,发现它是矩形.请你证明这个论;
(3)缜密小组在创新小组发现结论的基础上,量得图3中
,
,然后提出一个问题:将
沿着射线DB方向平移acm,得到
,连接
,使四边形
恰好为正方形,求a的值.请你解答此问题;
(4)请你参照以上操作,将图1中的
在同一平面内进行一次平移,得到
,在图4中画出平移后构造出的新图形,标明字母,说明平移及构图方法,写出你发现的结论,不必证明.
问题情境
在综合与实践课上,老师让同学们以“菱形纸片的剪拼”为主题开展数学活动,如图1,将一张菱形纸片ABCD(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc877716f9bf0a6a611570fabad1874c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6a783e5ffcf7a4ea9e531ea76199487.png)
操作发现
(1)将图1中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6a783e5ffcf7a4ea9e531ea76199487.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad77598eed14fb9d6619279b5bb51502.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bae492a42a40c74db0479d32a2abfab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70ed340e5eaf60970997c08f85786e94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e7cc884e7012d5e8bd142d28bb7a42f.png)
(2)创新小组将图1中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6a783e5ffcf7a4ea9e531ea76199487.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64ceeaa8823fab468bf3d154758ee96a.png)
示的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bae492a42a40c74db0479d32a2abfab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/990e6d825b91bbe46687b1539bd1b139.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28411a694cd4e3914cce1a6c21bed518.png)
(3)缜密小组在创新小组发现结论的基础上,量得图3中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e58dd2263a2136b4066801cf1bed34dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b60afcbfc2ba0be9c9d571c9f186ce8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bae492a42a40c74db0479d32a2abfab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70def9b4ba67f77c5bb336653b84cff2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/110d195a3dbfe59d8f83976814cdc501.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4986790d592e5375bb9a13d71c20c66e.png)
(4)请你参照以上操作,将图1中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6a783e5ffcf7a4ea9e531ea76199487.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3eaecfddbe565ebc72dd3e7ec4efeb4.png)
![](https://img.xkw.com/dksih/QBM/2016/7/11/1574217861308416/1574217867640832/STEM/cc69d44e-ee9f-4896-ac63-6944f8ef0c64.png)
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解答题-证明题
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真题
【推荐2】如图,菱形
的对角线
与
交于点
,
,
,
.
的值;
(2)求证:四边形
是矩形.
![](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/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2b5509bca53a7ec00c7ffadaa5ee7bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cccde778c619848076ea8c11b0b13a12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f1f406b3ff8561a371a39908fd813f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70606b1ac03c18dcba0e000f44dcda96.png)
(2)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5e89d43151016343d2ab6c4851565e7.png)
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