如图,在平行四边形ABCD中:
(1)尺规作图:作BC的垂直平分线EF,交BC于点E,交AD与点F;(不写作法,保留作图痕迹)
(2)连接DE并延长交AB的延长线于点G,求证:AG=2BG.
(1)尺规作图:作BC的垂直平分线EF,交BC于点E,交AD与点F;(不写作法,保留作图痕迹)
(2)连接DE并延长交AB的延长线于点G,求证:AG=2BG.
![](https://img.xkw.com/dksih/QBM/2021/7/9/2760281636372480/2796074796941312/STEM/b3e7c46d-2cc7-495b-b255-129a09c08e52.png)
更新时间:2021-08-28 20:11:38
|
相似题推荐
解答题-证明题
|
较易
(0.85)
【推荐1】如图,点B,C,D,E在一条直线上,
,
,
.求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/077d04feba1b55c079208435f7b561b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c3475a5c1df377e0805a88e72b11af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2710d1ae999c3297ce2b89c93754a462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ed6ee9282602607d9f0879cc73f6d1d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/10/8b454a22-f428-4256-86a3-efa199c2185d.png?resizew=200)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
【推荐2】如图,
,
,
,点E在线段
上.
;
(2)求
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56ee81929c987732fcb379802eeef7a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a1a6a4ec5e86330a295376d4302442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/898611813e24a744cd32df978e1e5c40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6cf0a8b91540e242ad7985683e0eafa.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
【推荐1】【实验】(1)如图①,点
为线段
的中点,线段
与
相交于点
,当
时,四边形
的形状为_________;
A.矩形 B.菱形 C.正方形 D.平行四边形
其理论依据是_________;
【探究】(2)如图②,在平行四边形
中,点
是
中点,过点
作
的垂线交边
于点
,连接
,试猜想
,
,
三条线段之间的数量关系,并给予证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/731016f5081dca7e5726598d757c0449.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/99393efa04579f3db5cf4f7e319f0440.png)
A.矩形 B.菱形 C.正方形 D.平行四边形
其理论依据是_________;
【探究】(2)如图②,在平行四边形
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/26/f9e0b49a-8645-4dd2-acb3-25c1e3289e0b.png?resizew=286)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
【推荐2】如图所示,人教版八年级上册数学教材P53数学活动中有这样一段描述:如图,四边形
中,
,
.我们把这种两组邻边分别相等的四边形叫做“筝形”.
(1)猜想筝形的对角线
与
有什么位置关系?并证明你的猜想;
(2)在“筝形”
中,已知
,请用含m,n的式子表示筝形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd95dc30c0344788b94289c464a3158e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4908fad3dc6fe1b0675c870328f043ef.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/8/17ba11cc-218a-4f67-9561-1bdee0884cb2.png?resizew=121)
(1)猜想筝形的对角线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
(2)在“筝形”
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff40dc81a29486593fe99039a30799b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
【推荐1】已知:线段
,直线
及
外一点
.
求作:
,使直角边
,垂足为点
,斜边
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
求作:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7281b641656a5992abaafb4190ca9afc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebf91d2cdb16a3e9392f2f943fee3c2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd64cfc4f355c60554b4f76c5ad17124.png)
![](https://img.xkw.com/dksih/QBM/2018/4/15/1924427230527488/1924842325123072/STEM/0b64da4392784693b1d4025ddd1b6f6c.png?resizew=289)
您最近一年使用:0次
解答题-作图题
|
较易
(0.85)
【推荐2】如图,在
中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/18/0afaa2d5-d554-4a92-b27a-34afb7566926.png?resizew=222)
(1)尺规作图:作
的垂直平分线交
于点
,交
于点
,连接
.(保留作图痕迹,不写作法,不写出结论)
(2)在(1)的条件下,若
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/18/0afaa2d5-d554-4a92-b27a-34afb7566926.png?resizew=222)
(1)尺规作图:作
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(2)在(1)的条件下,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e19a24762d0c926dec6f464a31df6648.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2947ca8e0cdbeb4aab80ce9e7b63ba98.png)
您最近一年使用:0次
解答题-作图题
|
较易
(0.85)
【推荐3】在数学课上,老师提出如下问题:
已知:∠α,直线l和l上两点A,B.
求作:Rt△ABC,使点C在直线l的上方,且∠ABC=90°,∠BAC=∠α.
![](https://img.xkw.com/dksih/QBM/2020/7/6/2500029222838272/2500269609222144/STEM/8207ed12e43e4c68952d0b0cd82a818c.png?resizew=390)
小刚的做法如下:
①以∠α的顶点O为圆心,任意长为半径作弧,交两边于M,N;以A为圆心,同样长为半径作弧,交直线l于点P;
②以P为圆心,MN的长为半径作弧,两弧交于点Q,作射线AQ;
③以B为圆心,任意长为半径作弧,交直线l于E,F;
④分别以E,F为圆心,大于
长为半径作弧,两弧在直线l上方交于点G,作射线BG;
⑤射线AQ与射线BG交于点C.Rt△ABC即为所求.
![](https://img.xkw.com/dksih/QBM/2020/7/6/2500029222838272/2500269609222144/STEM/725c1946b8c64540b27b19e0f356bac4.png?resizew=390)
(1)使用直尺和圆规,补全图形;(保留作图痕迹)
(2)完成下面的证明:
连接PQ
在△OMN和△AQP中,
∵ON=AP,PQ=NM,OM=AQ
∴△OMN ≌△AQP(__________)(填写推理依据)
∴∠PAQ=∠O=α
∵CE=CF,BE=BF
∴CB⊥EF(____________________________)(填写推理依据)
已知:∠α,直线l和l上两点A,B.
求作:Rt△ABC,使点C在直线l的上方,且∠ABC=90°,∠BAC=∠α.
![](https://img.xkw.com/dksih/QBM/2020/7/6/2500029222838272/2500269609222144/STEM/8207ed12e43e4c68952d0b0cd82a818c.png?resizew=390)
小刚的做法如下:
①以∠α的顶点O为圆心,任意长为半径作弧,交两边于M,N;以A为圆心,同样长为半径作弧,交直线l于点P;
②以P为圆心,MN的长为半径作弧,两弧交于点Q,作射线AQ;
③以B为圆心,任意长为半径作弧,交直线l于E,F;
④分别以E,F为圆心,大于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a889ac7cb3de4073ebd75c0cb737ace8.png)
⑤射线AQ与射线BG交于点C.Rt△ABC即为所求.
![](https://img.xkw.com/dksih/QBM/2020/7/6/2500029222838272/2500269609222144/STEM/725c1946b8c64540b27b19e0f356bac4.png?resizew=390)
(1)使用直尺和圆规,补全图形;(保留作图痕迹)
(2)完成下面的证明:
连接PQ
在△OMN和△AQP中,
∵ON=AP,PQ=NM,OM=AQ
∴△OMN ≌△AQP(__________)(填写推理依据)
∴∠PAQ=∠O=α
∵CE=CF,BE=BF
∴CB⊥EF(____________________________)(填写推理依据)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
【推荐1】如图,在平行四边形
中,
,垂足分别为点E,F,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5aaa063d2e7c4585a021929c6fa8505a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8ce1475f537b4ad21775bfaa16daa0c.png)
![](https://img.xkw.com/dksih/QBM/2021/6/19/2746327813169152/2746352303759360/STEM/f092e2b2-e78d-4f67-be8f-702aab7295e2.png)
您最近一年使用:0次
解答题-证明题
|
较易
(0.85)
名校
【推荐2】如图,在平行四边形
中,两条对角线
、
交于点O,点E为
延长线上的一点,且
,连接
,分别交
和
于点F和G,连接
,求证:
.
![](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/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4312c59b170d3f1f11abb896195f22b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](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/6cad4595d5352b2884568a59d8d766a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c25f1ccb3e56af0073e9b13f2039dee4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/4/d6def2fb-ebdc-4c69-91f6-31a915186673.png?resizew=174)
您最近一年使用:0次