如图,平行四边形
的对角线
、
交于点
,分别过点
、
作CF∥BD,DF∥AC,连接
交
于点
.
![](https://img.xkw.com/dksih/QBM/2020/6/26/2493107207602176/2494211000541184/STEM/58f6bf0d28e444eda6662a895fcb4fe9.png?resizew=216)
(1)求证:
;
(2)当
满足什么条件时,四边形
为菱形?请说明理由.
![](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/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://img.xkw.com/dksih/QBM/2020/6/26/2493107207602176/2494211000541184/STEM/58f6bf0d28e444eda6662a895fcb4fe9.png?resizew=216)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3a1d0dcc8874e97119426fe8c1ee8b0.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbced129627233661d88e9663a9e13c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d000a9d441370a43debf5845f5f41142.png)
更新时间:2020-06-28 08:28:10
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】已知:如图,∠BAC=∠DAM,AB=AN,∠B=∠ANM,求证:AD=AM.
![](https://img.xkw.com/dksih/QBM/2019/5/22/2208987984347136/2210598110978048/STEM/3692e98837f54e66bffb275a5fe5c837.png?resizew=192)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,在△ABC中,AB=AC,点D是BC的中点,BF⊥AC于点F,交AD于点E,∠BAC=45°.求证:△AEF≌△BCF.
![](https://img.xkw.com/dksih/QBM/2017/8/17/1754072769118208/1758023432241152/STEM/41d1a88f0a0947e7b8da6981a6ebc5bb.png?resizew=162)
您最近一年使用:0次
解答题-作图题
|
适中
(0.65)
名校
【推荐3】在学习正方形的过程中,小军发现一个规律:在正方形ABCD中,E为AD边上任意一点,连接BE,若过点A的直线
,交CD于点G,则必有
.为了验证此规律的正确性,小军的思路是:先利用下图,过点A作出BE的垂线,再通过证全等得出结论.请根据小军的思路完成以下作图与填空:
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/3/0ff7c9d4-e335-412e-9973-87197435f31d.png?resizew=141)
(1)用直尺和圆规在下图的基础上过点A作BE的垂线AG,交BE于点F,交CD于点G.(只保留作图痕迹)
(2)证明:∵四边形ABCD是正方形,
∴
①
,
,
∴
.
∵ ②
∴
,
∴
,
∴ ③ ,
在
和
中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b3aae1b288ff1214802d5347ef2923a.png)
∴
.
∴
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fdc5e36a59ce2f0c2208126033b4954.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb9feca8d384d09b47e5be73219658df.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/3/0ff7c9d4-e335-412e-9973-87197435f31d.png?resizew=141)
(1)用直尺和圆规在下图的基础上过点A作BE的垂线AG,交BE于点F,交CD于点G.(只保留作图痕迹)
(2)证明:∵四边形ABCD是正方形,
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4af17b55fa474f0103a858c2604b093.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0c06422e1d55db3077257af113df4bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d667c4527dc9910fc0c536aa1bbb3f0.png)
∵ ②
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a28c473b40b3cf82757682b7fb71486c.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecf45ef0a298fff057613c1589e8a67e.png)
∴ ③ ,
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad09a769a75b107390b9eeccc929f761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bbd6f0a0412d0f43ce1f7c1d530e56e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b3aae1b288ff1214802d5347ef2923a.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c20dbb30a6b86548e112935fec27802.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb9feca8d384d09b47e5be73219658df.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,
是平行四边形
的一条对角线,
,垂足分别是E、F.求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a7437ac06d7480f6c63165c26a24df6.png)
(2)四边形
是平行四边形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aac0d222d7960e63d43c212ac285d93c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a7437ac06d7480f6c63165c26a24df6.png)
(2)四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f3c15b30bd155641e548a7d8c172dd4.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】阅读与思考
下面是一位同学的数学学习笔记,请仔细阅读并完成相应任务.
完美四边形
定义:在平行四边形中,若有一条对角线的长是一边长的两倍,则这个平行四边形叫做“完美四边形”,其中这条对角线叫做完美对角线,这条边叫做完美边.
如图1、四边形
是平行四边形.
,
是
的中点,连接
,并延长
交
的延长线于点
,连接
.求证:四边形
是完美四边形.
是平行四边形,
∴
,即
,
∴
(依据1),
∵
是
的中点,
∴
.
在
和
中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ae089a3c501b7174418a8a5092f2d16.png)
∴
,
∴
,
∴四边形
是平行四边形(依据2).
,
,
∴四边形
是完美四边形.
任务:
(1)材料中的依据1是指 ;依据2是指 .
(2)如图2,在矩形
中,
,
是否存在值
,使得矩形
是完美四边形?若存在,求出
的值;若不存在,请说明理由.
下面是一位同学的数学学习笔记,请仔细阅读并完成相应任务.
完美四边形
定义:在平行四边形中,若有一条对角线的长是一边长的两倍,则这个平行四边形叫做“完美四边形”,其中这条对角线叫做完美对角线,这条边叫做完美边.
如图1、四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da851ec23b6a76c62280a1cf10fca6d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.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/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c08dc907e9b248bd49a7a087605e066a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42a876bc003f6c042c24ff4d8c11c8a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a11029ca6b4b9e7f777af0280cf163c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76644ca2e1256967f218b1f40c358ed3.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea296cdbe0e864151d2ed93ef1a73bd1.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cf5b86308e9f777a6611503ba8d0e9e.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/004104bafb5f30338123d4ea2b7fedde.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35e5a933a2a0ff3a28009cc989293ff5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ae089a3c501b7174418a8a5092f2d16.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3233cdff325c132e43842578292710b0.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17101383eb0787edaaa35adfcd20d5c9.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42a876bc003f6c042c24ff4d8c11c8a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb38a95899bba1f65d13c01baf9ac1b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16b46a2333254dd995f74b12def5c2e0.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42a876bc003f6c042c24ff4d8c11c8a8.png)
任务:
(1)材料中的依据1是指 ;依据2是指 .
(2)如图2,在矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3be96420ac78c8621fcb47a45514fa8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在四边形ABCD中,点H是BC的中点,作射线AH,在线段AH及其延长线上分别取点E,F,使EH=FH,连接BE,CF.
(1)求证:△BEH≌△CFH.
(2)当BH与EH满足什么关系时,四边形BFCE是矩形?
请说明理由.
(1)求证:△BEH≌△CFH.
(2)当BH与EH满足什么关系时,四边形BFCE是矩形?
请说明理由.
![](https://img.xkw.com/dksih/QBM/2014/10/10/1573752484102144/1573752490147840/STEM/3f977db766d243a69c160fdacfef9393.png)
您最近一年使用:0次
解答题-作图题
|
适中
(0.65)
【推荐2】如图,
是矩形
的对角线.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/22/9c0f16d5-69d5-4c1f-92c3-fa23070a0898.png?resizew=143)
(1)作
的垂直平分线
交
于点E,交
于点F(尺规作图,保留作图痕迹,不写作法和证明);
(2)在(1)所作的图形中,连接
,求证:四边形
是菱形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/22/9c0f16d5-69d5-4c1f-92c3-fa23070a0898.png?resizew=143)
(1)作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/167593eea25543e3b3c6f60e209e9b73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)在(1)所作的图形中,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fbe3114e3904346f34ffa843cbb3146.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910936ec9fb419d51ce2f5ea817f8401.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在四边形
中,
,
,
为对角线
的中点,
为边
的中点,连接
,
.
(1)求证:四边形
为菱形;
(2)连接
交
于
,若
,
,求四边形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0fff774b4b0087a6f304ce930d359be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f779e7f5f53e4377b9a0a8e945d562.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/a0ed1ec316bc54c37c4286c208f55667.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/49b50357a6545cae8348e3059312f520.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/11/837beb84-d9da-4d14-8639-a60e5844e66b.png?resizew=173)
(1)求证:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5eeb94acdc3de00655e6e29d5372da09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b515965c22d2950b592c096c6e3bdfd4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】已知:在
中,点
为
上一点,连接
,
的平分线交
于点
,过点
作
、
的平行线,分别交
、
、
于点
、
、
.
(1)如图
,求证:四边形DFEM为菱形;
(2)如图
,若
,点
为边
的中点,连接
、
,在不添加任何辅助线的情况下,请直接写出图
中的所有平行四边形(不包括以
为一边的平行四边形)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.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/3981e7286d41960daf4e110c1c84e03a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.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/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
(1)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
(2)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ed8f7d3d7043d4b1eb98fc5c4e2fcd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3533837e3d08c461dea031a44e5424d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/907d5147cea4c9ce855074864fe54506.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://img.xkw.com/dksih/QBM/2020/6/22/2490291354697728/2493603712262144/STEM/6f74d1de-3e58-442d-a237-3579f2203554.png?resizew=359)
您最近一年使用:0次