如图,点
是正方形
的边
上一动点(点
不与
、
重合),连接
,将
沿
翻折,使点
落在点
处.
最小时,
的值为 ;
(2)如图
,连接
并延长,交
的延长线于点
,在点
的运动过程中,
的大小是否变化,若变化,请说明理由;若不变,请求
的值;
(3)如图3,在(2)的条件下,连接
,试探索
、
、
之间的数量关系.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.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/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbfa1a2af7e38d33634c462300df381f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.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/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/515c3b8f365a3af3ab383a026aa04500.png)
(2)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/586e4b4d88e4b9b3faaaa3f913c94f43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/586e4b4d88e4b9b3faaaa3f913c94f43.png)
(3)如图3,在(2)的条件下,连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06e322e0c87479bba874db9ae9ba36b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a7e4a6765ce78b05ee97764771e01f.png)
更新时间:2024-05-09 13:36:23
|
相似题推荐
解答题-证明题
|
困难
(0.15)
【推荐1】如图1,两个等腰
,
有公共顶点
,
,
与
在同一直线上,连接
,
是
的中点,连接
、
,延长
,交
于
.
(1)求证:
;
(2)将图1中的
绕点
顺时针旋转
,连接
,
是
的中点,连接
、
、
,延长
交
于
,连接
,如图2,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f8f88798ec42a58dccd212586382b23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffff36e4dc6bcfea7dd5960d69082e6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63be8050066b82dde1113bc2b09f978a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5c62f22d7afc5627fcb86599faa8e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce6c0e9de83f2e64ae33609fc08459d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e429ea82b24cd48a27b7cb8a5cfa9357.png)
(2)将图1中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffff36e4dc6bcfea7dd5960d69082e6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b46c607b3deac746c0ef3389ad8f65c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c52e420485a3dd116914546086d22eb.png)
![](https://img.xkw.com/dksih/QBM/2020/5/6/2456906656980992/2457728471834624/STEM/68d6fbf6-1bc7-44b6-a8ef-7d0474eae9d8.png?resizew=558)
您最近一年使用:0次
解答题-问答题
|
困难
(0.15)
【推荐2】如图1,已知点
,
,且
、
满足
,平行四边形
的边
与
轴交于点
,且
为
中点,双曲线
上经过
、
两点.
________,
_________;
(2)求
点的坐标;
(3)点
在双曲线
,点
在
轴上(如图2),若以点
、
、
、
为顶点的四边形是平行四边形,请直接写出点
的坐标_____________________;
(4)以线段
为对角线作正方形
(如图3),点
是边
上一动点,
是
的中点,
,交
于
,当
在
上运动时,
的值是否发生改变?若改变,求出其变化范围;若不改变,请求出其值,并给出你的证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4b9486ec9dca95979803bf91ca6c337.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fa6e5a12543f954be1a6057c6b2ed51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36fd2c0f64e5ef043d60307896ddd133.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07854693dd2e33f66030d6106eb6e0ee.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/380bbacf854e30e2e747fc286d2b9997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ccd4162c7d09f970cb77cadacdbe521.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
(3)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07854693dd2e33f66030d6106eb6e0ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
(4)以线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52f7cdcbc721fbde7d5bd0afbf07b529.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d030bc03d5e8e2bbd79de338a7c375ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e605a9ab715e068a48f3d71cd35dc8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96011b527f818364cfe804a39a0e77a7.png)
您最近一年使用:0次
解答题-问答题
|
困难
(0.15)
【推荐1】如图,在平面直角坐标系中,已知抛物线
与
轴交于
两点(点
在点
的左侧),与
轴交于点
,顶点为
,连接
.
的坐标;
(2)如图1,连接
并延长交
的延长线于点
,求
的度数;
(3)若点
是抛物线对称轴上一动点,点
为坐标平面内一点,是否存在以
为边,点
、
、
、
为顶点的四边形是菱形,若存在,请直接写出点
的坐标;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0c9800e4b992044d16681e77ff6563c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0565aa433ff7dbba0d3867ba4b75e2f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
(2)如图1,连接
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a55a1a244f81097e05e715b69580faa.png)
(3)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.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/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
您最近一年使用:0次
解答题-证明题
|
困难
(0.15)
【推荐2】已知:
内接于
,其中
,连接
.
![](https://img.xkw.com/dksih/QBM/2022/3/29/2946651606614016/2957525801926656/STEM/40b34f8e-02a3-4c56-9630-68eebc0825ea.png?resizew=433)
(1)如图1,求证:
平分
;
(2)如图2,点D在
上,连接
,若
,求
的度数;
(3)如图3,在(2)的条件下,
交
于点E,若
,求线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://img.xkw.com/dksih/QBM/2022/3/29/2946651606614016/2957525801926656/STEM/40b34f8e-02a3-4c56-9630-68eebc0825ea.png?resizew=433)
(1)如图1,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2c3d2cba96f6f03520c0b3f6e4da03e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
(2)如图2,点D在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/667349d99185bb045030b733352ff7fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0eb0c11e4b7aa9030a6691aee35eed0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b52a719b88337e5ad028303bcc0a3994.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdb8eca20ce2c918ea4034ea15210c7f.png)
(3)如图3,在(2)的条件下,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/511154df785c1814e6b4c9346fb49b64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
您最近一年使用:0次
解答题-证明题
|
困难
(0.15)
解题方法
【推荐1】在△ABC中,D是边BC的中点.
(1)①如图1,求证:△ABD和△ACD的面积相等;
②如图2,延长AD至E,使DE=AD,连结CE,求证:AB=EC.
(2)当∠BAC=90°时,可以结合利用以上各题的结论,解决下列问题:
①求证:AD
BC(即:直角三角形斜边上的中线等于斜边的一半);
②已知BC=4,将△ABD沿AD所在直线翻折,得到△ADB',若△ADB'与△ABC重合部分的面积等于△ABC面积的
,请画出图形(草图)并求出AC的长度.
(1)①如图1,求证:△ABD和△ACD的面积相等;
②如图2,延长AD至E,使DE=AD,连结CE,求证:AB=EC.
(2)当∠BAC=90°时,可以结合利用以上各题的结论,解决下列问题:
①求证:AD
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a50a39604477d1d9326eb455cda2e838.png)
②已知BC=4,将△ABD沿AD所在直线翻折,得到△ADB',若△ADB'与△ABC重合部分的面积等于△ABC面积的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d266a04f3dc7483eddbc26c5e487db.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/17/cf8122a3-0fa1-435d-9f03-751c8da46750.png?resizew=282)
您最近一年使用:0次
解答题-证明题
|
困难
(0.15)
名校
【推荐2】如图,ABC为
的内接三角边形,AD为
的切线交CB延长线于点D,点A为切点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/29/6f79c687-b8b8-44e0-bfcf-2b5845788209.png?resizew=500)
(1)如图1,求证:
.
(2)如图2,点E在优弧BC上,若
.求证:
;
(3)如图3,在(2)的条件下,AF为
的直径,交BC于点G,交CE于点L,若
,EA交BC于点H,
,
时,求线段CL的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/29/6f79c687-b8b8-44e0-bfcf-2b5845788209.png?resizew=500)
(1)如图1,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84b711ff901467a5a91ff3730bd65964.png)
(2)如图2,点E在优弧BC上,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c549260b225d5bb892ead3b8a39dbab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fc13fe21e64d9b45614ed43be847904.png)
(3)如图3,在(2)的条件下,AF为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afba63c9ddb4c2d8106846bffc3f29ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50c95115b95f0fd72cfb493e468fd5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0950a2e768bfc39dc3ae75b489d7c3d5.png)
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解答题-问答题
|
困难
(0.15)
【推荐3】如图,在
中,
,
,
.动点P从点C出发,沿CA以每秒1个单位长度的速度向终点A运动,同时动点Q从点B出发,沿BC以相同的速度向终点C运动,当点P到点A时,点Q同时停止运动.连结
,以
、
为边作平行四边形
.设点P的运动时间为t秒
.
的长为____________.
(2)当点H落在边
上时,求
的值.
(3)当平行四边形
是轴对称图形时,求
的值.
(4)沿过点Q且垂直于
的直线将平行四边形
剪开,得到两个图形,用这两个图形拼成不重叠且无缝隙的图形恰好是三角形.直接写出所有符合上述条件的
值.
![](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/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb6ede9761b5b90f8dc137708e1ee90f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be3e1c04682a1086128c30c9f35175e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07eabb3ff92cc5e071c48df759e64ab8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)当点H落在边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7885a96dbd8636e42b9e1001c1cbb03a.png)
(3)当平行四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be3e1c04682a1086128c30c9f35175e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(4)沿过点Q且垂直于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be3e1c04682a1086128c30c9f35175e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
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【推荐1】问题情境
在综合实践课上,同学们以“正方形和直线的旋转”为主题分组开展数学探究活动,已知正方形ABCD,直线PQ经过点A,并绕点A旋转,作点B关于直线PQ的对称点E,直线DE交直线PQ于点F,连结AE,BE.
![](https://img.xkw.com/dksih/QBM/2020/6/9/2480956494127104/2481753503170560/STEM/0de25f6a5c494099a7754be2d50e5bb8.png?resizew=355)
操作发现
(1)如图1,设∠PAB=25°则∠ADF= °.
(2)“梦想小组”的同学们发现,∠BEF的度数是一个定值,这个值为 .
(3)“创新小组”的同学们发现,线段AB、DF、EF之间存在特殊的数量关系,请写出这一关系式,并说明理由:
拓展应用
(4)如图2,当直线PQ在正方形ABCD的外部时,“进取小组”的同学们发现(3)的结论仍然成立,并提出新问题;若DF=3
,EF=4
,直接写出正方形ABCD的边长.
在综合实践课上,同学们以“正方形和直线的旋转”为主题分组开展数学探究活动,已知正方形ABCD,直线PQ经过点A,并绕点A旋转,作点B关于直线PQ的对称点E,直线DE交直线PQ于点F,连结AE,BE.
![](https://img.xkw.com/dksih/QBM/2020/6/9/2480956494127104/2481753503170560/STEM/0de25f6a5c494099a7754be2d50e5bb8.png?resizew=355)
操作发现
(1)如图1,设∠PAB=25°则∠ADF= °.
(2)“梦想小组”的同学们发现,∠BEF的度数是一个定值,这个值为 .
(3)“创新小组”的同学们发现,线段AB、DF、EF之间存在特殊的数量关系,请写出这一关系式,并说明理由:
拓展应用
(4)如图2,当直线PQ在正方形ABCD的外部时,“进取小组”的同学们发现(3)的结论仍然成立,并提出新问题;若DF=3
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
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解答题-证明题
|
困难
(0.15)
【推荐2】苏科版八下数学教材中,对正方形的性质和判定进行了探究,同时课本94页第19题对正方形中特殊线段的位置和数量关系也进行了探究,在此,我们也来作进一步的探究,如图1,探究所提供的正方形
的边长都为2.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/25/f59bc153-58a2-444d-b8a8-a370c4af87a6.png?resizew=316)
【探究】
(1)如图2,在正方形
中,如果点E、F分别在
、
上,且
,垂足为M,那么
与
相等吗?证明你的结论.
【应用】
(2)如图3,在正方形
中,动点E、F分别在边
、
上,将正方形
沿直线
折叠,使点B对应的点M始终落在边
上(点M不与点A、D重合),点C落在点N处,
与
交于点P,设
,求线段
的长(用含t的式子表示).
【拓展】
(3)如图4,在正方形
中,E是
的中点,F、G分别是
、
上的动点,且
,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/25/f59bc153-58a2-444d-b8a8-a370c4af87a6.png?resizew=316)
【探究】
(1)如图2,在正方形
![](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/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4e22ba3e6e1c1d6b12d9b8baa8d1f02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
【应用】
(2)如图3,在正方形
![](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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43a387e25219d186235ae6ad0295a270.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1460aa3d83df61f6c411b34412135451.png)
【拓展】
(3)如图4,在正方形
![](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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82d3a004c4f6c29bd52364eb658c704b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c31bb6924117fac5205f3d818313143.png)
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