如图,在
中,
,点D,E分别是边AB,AC的中点,延长BC至F,使
,连接CD.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/31/8508f497-8d0f-4466-b1ab-ef23fd84f147.png?resizew=143)
(1)求证:四边形DEFC是平行四边形;
(2)若
,求EF的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a3677b2682fb3572f6f3ae7b7d8ad1e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/31/8508f497-8d0f-4466-b1ab-ef23fd84f147.png?resizew=143)
(1)求证:四边形DEFC是平行四边形;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc34db5860990e51ba31edc8cdd077c2.png)
更新时间:2022-07-31 00:42:24
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相似题推荐
解答题-证明题
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【推荐1】如图,在
中,
是
延长线上一点,
是
延长线上一点,且
,求证:
.
![](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/67d822262ff00915910e5b87d81ad1ba.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
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![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/11/fde136b9-36c6-45ae-af0f-52e2f6864c49.png?resizew=193)
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【推荐2】已知:如图,四边形
是菱形,连接对角线
,过点
作
交
的延长线于点
,过点
作
交
的延长线于点
,连接
.
求证:四边形
是矩形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5e89d43151016343d2ab6c4851565e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1082dd7e08556354aa7d4861d419e4c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdc93e193fad261689949a52819753f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aa1162d5481e2441fe5bc0d49a576b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf1438142deeac876fc7dc50552e552.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/3/8d3ac59c-6161-4bd2-be59-34f199d12aa6.png?resizew=182)
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解答题-问答题
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【推荐1】在菱形
中,点
是边
的中点,试分别在下列两个图形中按要求使用无刻度的直尺画图.
(1)在图1中,过点
画
的平行线;
(2)在图2中,连接
,在
上找一点
,使点
到点
,
的距离之和最短.
![](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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
(1)在图1中,过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)在图2中,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/19/66bf74ed-4a10-4455-8e00-1f33ead6f494.png?resizew=321)
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【推荐2】如图,在△ABC中,点D,E,F分别是AB,BC,CA的中点,AH是边BC上的高.
(1)试判断线段DE与FH之间的数量关系,并说明理由;
(2)求证:∠DHF=∠DEF.
(1)试判断线段DE与FH之间的数量关系,并说明理由;
(2)求证:∠DHF=∠DEF.
![](https://img.xkw.com/dksih/QBM/2019/2/21/2145361130225664/2146877069623296/STEM/43d34cea156842c8889815c32ca945d3.png?resizew=165)
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【推荐1】如图,在△ABC中,AD⊥CA于点A,交BC于点D,M是CD的中点,连接AM,AM=AB.
![](https://img.xkw.com/dksih/QBM/2016/2/23/1573974814621696/1573974820880384/STEM/eead74568783480db13b5e3a40e8f8c6.png)
(1)求证:CD=2AB;
(2)若AC=8,AB=5,求AD的长.
![](https://img.xkw.com/dksih/QBM/2016/2/23/1573974814621696/1573974820880384/STEM/eead74568783480db13b5e3a40e8f8c6.png)
(1)求证:CD=2AB;
(2)若AC=8,AB=5,求AD的长.
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解答题-证明题
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【推荐2】如图,直线
、
相交于点
,
、
分别是直线
、
上两点且
,
,点
、
是
、
的中点.
求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d97dc3b752832906de41447bb58a341.png)
求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee50a23604ea2a9c1f3649dab97c2e7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/18/02d91976-05de-4de5-8a53-7c05138c0c29.png?resizew=223)
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