如图1,已知正方形ABCD,点E是边BA边上一动点(不与点A、B重合),连接CE.将三角形CBE沿着BA方向平移,使得BC边与AD边重合,得到三角形DAF.
![](https://img.xkw.com/dksih/QBM/2019/5/16/2205023308324864/2207248275513344/STEM/952dfffe4c774631b2695e2064fd55e8.png?resizew=521)
(1)四边形CEFD能否是一个菱形?说明理由;
(2)在图1的基础上,连接AC,过点E作EG垂直AC于点G,如图2.
①若已知∠BEC=70
,求∠CEG的度数;
②如图3,连接GD、GF.求证:GD=GF;
③若三角形CGD为等腰三角形,求∠CEG的度数.
![](https://img.xkw.com/dksih/QBM/2019/5/16/2205023308324864/2207248275513344/STEM/952dfffe4c774631b2695e2064fd55e8.png?resizew=521)
(1)四边形CEFD能否是一个菱形?说明理由;
(2)在图1的基础上,连接AC,过点E作EG垂直AC于点G,如图2.
①若已知∠BEC=70
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83873a9d782f2588c5eedbfe73f9bc2f.png)
②如图3,连接GD、GF.求证:GD=GF;
③若三角形CGD为等腰三角形,求∠CEG的度数.
更新时间:2019-05-19 22:01:01
|
相似题推荐
解答题-问答题
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【推荐1】如图,点
,将线段OA平移至线段BC,
.
![](https://img.xkw.com/dksih/QBM/2022/4/25/2965880384610304/2972678317539328/STEM/c7652fd6-de72-472f-a733-48ff26626503.png?resizew=127)
(1)请直接写出点C的坐标:
(2)若
,点P为y轴上一动点(点P不与原点重合,点P不在直线BC上).试探究∠CPO与∠BCP之间的数量关系.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3dd80e657a2a9ad2dcf6ff6905d688e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e15dae32953862fc6fbfb29645894a50.png)
![](https://img.xkw.com/dksih/QBM/2022/4/25/2965880384610304/2972678317539328/STEM/c7652fd6-de72-472f-a733-48ff26626503.png?resizew=127)
(1)请直接写出点C的坐标:
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc1eb76fe74cba30f7cbcde349ba80da.png)
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【推荐2】理解与探究:
构造辅助线是一种探究和解决数学几何问题常用的方法,通过构造适当的辅助线,将条件中隐含的有关图形的性质充分揭示出来,以便取得过渡性的结论,达到推导出结论的目的.请根据下列材料解决问题:
【问题理解】
(1)在数学课上,老师提出如下问题:如图,
中,若
是
边上的中线,且
.问:
与
有怎样的数量关系?
小李同学经过观察和思考,提出
的猜想结论,并给出了证明其猜想的方法:
如图1.延长中线
到点
,使
,连接
,则容易证得
.
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efec694f0e0b9049acd183369ab56edb.png)
而![](https://staticzujuan.xkw.com/quesimg/Upload/formula/318178589d37649398dc39b9f5c86595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2269abc697fc1c77271282aa0be25e0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d55b06ea239551eb6f5f9c2eccdb37a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/642ef1688879900bb80a876a3159e07d.png)
小李同学的上述解决问题的方法当中,其证明
的判定依据是:________.(填
或
或
或
)
【探索发现】
(2)如图2,
中,
,
,若
是
延长线上一点,连接
,以
为腰作等腰直角三角形
,且
.小李同学连接
后(如图3),发现
且
.请证明他的结论.
【方法迁移】
(3)在(2)的条件下,取
的中点
,连接
和
,如图4,请判断
与
有怎样的数量关系和位置关系?并说明理由.
构造辅助线是一种探究和解决数学几何问题常用的方法,通过构造适当的辅助线,将条件中隐含的有关图形的性质充分揭示出来,以便取得过渡性的结论,达到推导出结论的目的.请根据下列材料解决问题:
【问题理解】
(1)在数学课上,老师提出如下问题:如图,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/3e051da5c8aea7ef4a467bfaa07256b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/3/80071801-c471-4c09-92a4-e0e25a8fc153.png?resizew=120)
小李同学经过观察和思考,提出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b10134e7a46e6f6f7cb9d5e2371727d.png)
如图1.延长中线
![](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/d0fa1aa5a7a5bb172ed4603f17c8b2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af7d19b5c22d55256a532764d4a8a5b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9029a1df0c460535d3cfc068b85cc05e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efec694f0e0b9049acd183369ab56edb.png)
而
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/318178589d37649398dc39b9f5c86595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2269abc697fc1c77271282aa0be25e0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d55b06ea239551eb6f5f9c2eccdb37a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/642ef1688879900bb80a876a3159e07d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/3/7bf15767-1b1b-4203-8f59-6ee779b3c63e.png?resizew=121)
小李同学的上述解决问题的方法当中,其证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af7d19b5c22d55256a532764d4a8a5b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6720e36b02193db161c61d4017673760.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5a290f047f50481318d040c604d72f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4351a730f61bb998bab8f0b7848912d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9beb8b968744573e593ac28451c69729.png)
【探索发现】
(2)如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b10134e7a46e6f6f7cb9d5e2371727d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88ef49a4fcf91b1c60bbd38ac51295fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eba7e2cb2e2390673b83bde332973d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eac6f98ed81727dc5f6699ea5117fff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84be64d28b1623e71ad989f37336b1f2.png)
【方法迁移】
(3)在(2)的条件下,取
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/3/c4143874-54d9-416b-8439-56c6f3f6b82e.png?resizew=421)
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【推荐3】补全解答过程:
(1)如图,线段AC=4,线段BC=9,点M是AC的中点,在CB上取一点N,CN:NB=1:2,求MN的长.
![](https://img.xkw.com/dksih/QBM/2020/2/13/2398071913275392/2398194964897792/STEM/a98b2a58305a4003b18320f8fcea4b71.png?resizew=212)
解:∵M是AC的中点,AC=4,
∴MC=
(填线段名称)= ,
又因为CN:NB=1:2,BC=9,
∴CN=
(填线段名称)= .
∴MN= (填线段名称)+ (填线段名称)=5.
∴MN的长为5.
(2)已知:如图,直线AB∥CD,直线EF与直线AB,CD分别交于点G,H;GM平分∠FGB,∠3=60°.求∠1的度数.
![](https://img.xkw.com/dksih/QBM/2020/2/13/2398071913275392/2398194964897792/STEM/4359c034acb74ecba8f4586f8c9ccf6e.png?resizew=187)
解:∵EF与CD交于点H,(已知)
∴∠3=∠4.( )
∵∠3=60°,( )
∴∠4=60°.
∵AB∥CD,EF与AB,CD交于点G,H,(已知)
∴∠4+∠FGB=180°.( )
∴∠FGB= .
∵GM平分∠FGB,(已知)
∴∠1= °.(角平分线的定义)
(1)如图,线段AC=4,线段BC=9,点M是AC的中点,在CB上取一点N,CN:NB=1:2,求MN的长.
![](https://img.xkw.com/dksih/QBM/2020/2/13/2398071913275392/2398194964897792/STEM/a98b2a58305a4003b18320f8fcea4b71.png?resizew=212)
解:∵M是AC的中点,AC=4,
∴MC=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
又因为CN:NB=1:2,BC=9,
∴CN=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
∴MN= (填线段名称)+ (填线段名称)=5.
∴MN的长为5.
(2)已知:如图,直线AB∥CD,直线EF与直线AB,CD分别交于点G,H;GM平分∠FGB,∠3=60°.求∠1的度数.
![](https://img.xkw.com/dksih/QBM/2020/2/13/2398071913275392/2398194964897792/STEM/4359c034acb74ecba8f4586f8c9ccf6e.png?resizew=187)
解:∵EF与CD交于点H,(已知)
∴∠3=∠4.( )
∵∠3=60°,( )
∴∠4=60°.
∵AB∥CD,EF与AB,CD交于点G,H,(已知)
∴∠4+∠FGB=180°.( )
∴∠FGB= .
∵GM平分∠FGB,(已知)
∴∠1= °.(角平分线的定义)
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【推荐1】如图,等腰
中,
,
于点D,点E在线段
的左侧且
.
![](https://img.xkw.com/dksih/QBM/2022/11/28/3119391060582400/3120864328204288/STEM/aca9074a01cf4b5a82910a38b6441429.png?resizew=131)
(1)求证:
;
(2)若点F在
的延长线上,求证:
平分
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3c65edad25ddd666cdce0d7e5afefc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9559e99d7bcc4b382356486dd255dc15.png)
![](https://img.xkw.com/dksih/QBM/2022/11/28/3119391060582400/3120864328204288/STEM/aca9074a01cf4b5a82910a38b6441429.png?resizew=131)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acee1987b504c51650f055eaa0be2836.png)
(2)若点F在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adcae9d00980803e5955228d1e217abe.png)
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解答题-问答题
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【推荐2】在
中,三点
、
、
是逆时针顺序,
,
是
边上的动点,
,三点
、
、
也是逆时针顺序,
.
(1)当
时,过点
作
,垂足为点
.
如图
,若点
与点
重合,则
的度数为______;
如图
,点
到
的距离等于______;
.线段
的长
.线段
的长
.线段
的长
.线段
的长
(2)如图
.当
时,
试说明:点
到
的距离等于线段
的长;
连接
交
于点
,试说明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a55b6ce55e67f6e95e616eaf1ca3f6f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/398150fc1981148caed16de53ed56bf3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/29/8b1f0d31-580f-4399-9409-1308627ca530.png?resizew=438)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c69a23d106fd34aa17b22e9c9a8de36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24ad0a87392245e4bf5bafe26089803b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e1c9ae241fd78126274c65e17990c88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23dc2d2dd56fcc67698c45a6e0e48f80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c650fe55b7603f106c53ca2423451c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff4489d9b83072184c0e1d6b09be50ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6655e2fa64a32cd12fe0279afd65d73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea1e8babee63bfc889ae5a34632284bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3064b70f24e9bbcab76e0dc61274b9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca66a268d6f46e0e9d5d9151b785be60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f0b669ef4514f24ee09adeff7f41238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/184921a45f87423e92cf1e627ad55143.png)
(2)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33ac762a2899a58faa0d3ab44f1281fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e1c9ae241fd78126274c65e17990c88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c650fe55b7603f106c53ca2423451c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eedae8d316c76e3d0b451256de03fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dbd532bae76246a0d6f9f31ea6a2c73.png)
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解答题-问答题
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较难
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名校
【推荐1】如图,已知
中,
,
,动点
沿
方向从点C向点
运动,同时,动点
沿
方向从点
向点
运动,速度都为每秒1个单位长度,
,
中任意一点到达终点时,另一点也随之停止运动,过点
作
//
,交
边于点
,连结
,设
,
的运动时间为
.
![](https://img.xkw.com/dksih/QBM/2021/12/6/2866612369866752/2869465469927424/STEM/b5f38d5e-fe03-4153-a253-80438812647b.png?resizew=148)
(1)直接写出
的长;(用含
的代数式表示)
(2)若
,求当
为何值时,
与
相似.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d59cdc4d6fa9e28e0d7ce6ea74833bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ebb33adb2310a6e03918761e68204a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9abaeba15f3abdd877bc701af52c5cd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.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/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.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/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3525ddc5153fada64eaf14e50b536542.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/36a1b09c653185842513e24ebba60bb3.png)
![](https://img.xkw.com/dksih/QBM/2021/12/6/2866612369866752/2869465469927424/STEM/b5f38d5e-fe03-4153-a253-80438812647b.png?resizew=148)
(1)直接写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efbebc3df0e44aaf7c04feebcf5d70dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3da7bcea5a45eeae211f5851f12a7517.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab142c659d5434d88d7f6f5d994cfd18.png)
您最近一年使用:0次
解答题-证明题
|
较难
(0.4)
【推荐2】如图,在
中,
,在
中,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/26/d5a79947-3066-47cc-8977-ff7a2c59ef12.png?resizew=105)
(1)试说明
与
满足什么等量关系时,点D、点C、点E三点共线.
(2)连接
,连接
交
于F点,若点F恰好是线段
的中点,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/893559f79d779b9a5b12ee929d6cfed4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd66f89184ca925f4575c26053decf2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec2c1f3a53a2c5bf175dc9093be83f7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/489382983e41516ea36d0f30f4a272c1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/26/d5a79947-3066-47cc-8977-ff7a2c59ef12.png?resizew=105)
(1)试说明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d29e7c4d6216690152430b09f9cf0c2.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1d17868ca269aa1471f3eeebd85a5e7.png)
您最近一年使用:0次
解答题-证明题
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较难
(0.4)
【推荐1】已知:如图①,在正方形
中,点M为
的中点,
,且
交正方形
的外角平分线并点N.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/5/24/52ba614a-598c-4aee-99f9-bbdc87d800e4.png?resizew=376)
(1)求证:
.
(2)若将条件中的“点M为
的中点”去掉,当点 M为线段
上任意一点时,其他条件不变,上面的结论还成立吗?如果成立请给出推理证明;若不成立,请说出理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7077d46a1c3adcecae7c32c6e195c33c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa29fe6cd9eb51c184f6299d437375cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb3f9a5da641be35117fd35ba07a6aa.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/5/24/52ba614a-598c-4aee-99f9-bbdc87d800e4.png?resizew=376)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b756478d3b60a27cd2c4245db5a9ff32.png)
(2)若将条件中的“点M为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
您最近一年使用:0次
解答题-问答题
|
较难
(0.4)
【推荐2】如图,点P是正方形ABCD边AB上一点(点P不与点A,B重合),连接PD,将线段PD绕点P顺时针方向旋转90°得到线段PE,PE交边BC于点F,连接BE,DF.
(1)求∠PBE的度数;
(2)若△PFD∽△BFP,求
的值.
(1)求∠PBE的度数;
(2)若△PFD∽△BFP,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41ab40260ac9056153d14d70d2519371.png)
![](https://img.xkw.com/dksih/QBM/2018/4/11/1921685056405504/1922446954520576/STEM/625adf56e6634d988e8b91d266d82fa4.png?resizew=180)
您最近一年使用:0次