在
中,
是
边上的中线,点
在射线
上,过点
作
交
的延长线于点
.
(1)如图1,点
在
边上,
与
交于点
证明:
;
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/5/ae663dbc-3aec-4e6d-8207-b3386d366b02.png?resizew=160)
(2)如图2,点
在
的延长线上,
与
交于点![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8fbc229c957487495bb8cda1d4cfd8e.png)
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/5/8c084ef3-1069-423a-b011-b59d516d538f.png?resizew=156)
①求
的值;
②若
,求
的值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa481a77368aaca27746f70a0522143b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.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/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bd92bf75d2adb72311780e571ea6445.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
(1)如图1,点
![](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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8fbc229c957487495bb8cda1d4cfd8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c27081d595c4e9a86ad9fc47b09f0ee8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/5/ae663dbc-3aec-4e6d-8207-b3386d366b02.png?resizew=160)
(2)如图2,点
![](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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8fbc229c957487495bb8cda1d4cfd8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53b4b29aeeb1520a6b74de9b6f1d8c32.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/5/8c084ef3-1069-423a-b011-b59d516d538f.png?resizew=156)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/219679f2c28a0418f62d9861b7aec02f.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ee232abab37a79f9f97f1fd3f7154af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cdba1337ec85fa9722cb4b320a82ae6.png)
更新时间:2020-07-06 13:09:35
|
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】如图,已知
,且
,点
是射线
上一动点(不与点
重合),
,
分别平分
和
.交射线
于点
,
.
![](https://img.xkw.com/dksih/QBM/2020/4/14/2441496751054848/2441917005586432/STEM/78899ad591eb45f983a4963ee439e51e.png?resizew=240)
(1)求
的度数;
(2)当点
运动到使
时,求
的度数;
(3)在点
运动过程中,
与
之间是否存在一定数量关系?若存在,请写出它们之间的数量关系,并说明理由;若不存在,请举出反例.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95504a760124acd0682fb1c896ad74e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d777d15cd733338ecfd0ea63819f62c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac3c1375c64dceef45846308a418cf7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/028012ef88546694cd67ac0d44bf6725.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f50b3ae183997b707d16eb4e7f6712fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://img.xkw.com/dksih/QBM/2020/4/14/2441496751054848/2441917005586432/STEM/78899ad591eb45f983a4963ee439e51e.png?resizew=240)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fbf1667b21a273bf5dd007d65eeda7c.png)
(2)当点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9256a9a29859edb077189bd91d8aa93d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb686e4f5e3938575bc547e849d5513f.png)
(3)在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/715c21f2228f0ac61aa5b7a52329eaf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed8c43341c982e729dcd6c3b178865f8.png)
您最近一年使用:0次
解答题-作图题
|
适中
(0.65)
名校
【推荐1】如图,在
中,
,
.
(1)尺规作图:作
的垂直平分线,交
于E,交
于D,交BC于点O(保留作图痕迹,不写作法);
(2)连接
、
,求证:四边形
是平行四边形.
证明:∵![](https://staticzujuan.xkw.com/quesimg/Upload/formula/930d36961606e3538422da9a0c48e440.png)
∴
___________①___________
∵
垂直平分![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
∴___________②___________![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f7d3aa04a49bacf9df22e70dc72802c.png)
在
和
中:
∴![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c9c3e1ae3da61dbe2fc5f30447e07ef.png)
∴
___________④___________
又∵___________⑤___________
∴四边形
是平行四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f89deb952f57f4b3fa4887b098b7b91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/930d36961606e3538422da9a0c48e440.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/27/3dbee18a-bcb6-4943-af3c-807211b6a59e.png?resizew=209)
(1)尺规作图:作
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcdae78f4d3b8d8213ac3ac9a9567eb5.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adfe2a58326612fcabd34fd4402a66ee.png)
证明:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/930d36961606e3538422da9a0c48e440.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2350fe8426a29f5dc63c7fdda29b2ea.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21037e170bdbb322558e79c40c00b454.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
∴___________②___________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f7d3aa04a49bacf9df22e70dc72802c.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6398f2557943357934d2858366fdbb09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/793184a2bf5179782886c5cd3dc04a18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce56a4a00fc3c13f4d45f61810559479.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c9c3e1ae3da61dbe2fc5f30447e07ef.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c978d92edf0c4c1ef8620c17df75d35e.png)
又∵___________⑤___________
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adfe2a58326612fcabd34fd4402a66ee.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】如图,
内接于
,
,点
是
的中点.
,
边上的高
,
相交于点
.试证明:
(1)
;
(2)四边形
是菱形.
![](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/b57fdd2a3642716fcf5100011eb3ec88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed41d321f4c0717ac5b443aad942d9a7.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/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ef6b877ef41416519b1c7b45c0ba5b4.png)
(2)四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/840a83ce113a5d3c64c02cbb4bb47ef4.png)
![](https://img.xkw.com/dksih/QBM/2020/11/3/2585002446413824/2600743336812544/STEM/97fc76db-083c-4f35-acca-60a7292e1f4d.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】阅读并完成以下填空:
如图1,已知:
为
的中线,求证
.
证明:延长
至
使得
.连接
,则
.
∵
为
的中线,
∴
.
在
和
中,
, , .
∴
.
∴
.
在
中,根据三角形的三边关系有
.
而
,
∴
.
这种添加辅助线的方法,我们称为“倍长中线法”.
请利用这种方法解决下列问题:
问题1:如图2,在
中,
,
,
为
的中点,
.求
的面积.
问题2:如图3,在
中,
是三角形的中线.点
在中线
上,且
,连接并延长
交
于点
.求证
.
如图1,已知:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d168264acad9c8eab2ec4176916dc3.png)
证明:延长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ad98ad714864041a632ca949308e417.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8619670131d071cadcecb99cf18c2e6d.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/532aece6cfd67e2a97977eed978dbf2b.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73892892025e13b6d45f88a266b1fe6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/532aece6cfd67e2a97977eed978dbf2b.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77f78e9e3d07db0ec5062129e5b50128.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cd1f3b67f266fc83774bc59ef8b90a1.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb49df05f2e31d005735c3f14a21d30.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa9de43643bd41a661dc0120d3d63754.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
而
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f943063dc9d9149a4aa60e3a4a1a5a74.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11d168264acad9c8eab2ec4176916dc3.png)
这种添加辅助线的方法,我们称为“倍长中线法”.
请利用这种方法解决下列问题:
问题1:如图2,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3ad4c0ba3a6750537789844d0ec419d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f25936291abb6432ed5a710ebf0ea195.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/1326e85ff750d882de9ea65c29e3d3b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
问题2:如图3,在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe8bb808edb7f81fb3c14c8f3d7f0fad.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://staticzujuan.xkw.com/quesimg/Upload/formula/3767efa8adfb71001ad39df9560cbf6a.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】如图,在
中,
,
,垂足为
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/203e4be7-a543-4312-a00e-27b8984af19e.png?resizew=369)
(1)证明:
;
(2)若
,
,求
的长度;
(3)若
,
,点
是线段
上一点,当
时,求点P到直线AC的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b757f0c42ae5c9a2d6a4b19e5877b27.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/21/203e4be7-a543-4312-a00e-27b8984af19e.png?resizew=369)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7506a5dbd75e7d59d598325119ca958.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a7b5adfcac0f46a4cd19da4ebb4a2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c1ac2e11788860424508ea9e80cf89d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55c24a968c73e960698a572ab01e3698.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfb08f6a798dc293f3d8de281190f65e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/967d48b84e17cd186684b9e25fe2da27.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
真题
名校
【推荐1】在△ABC和△ADE中,BA=BC,DA=DE,且∠ABC=∠ADE=
,点E在△ABC的内部,连接EC,EB和BD,并且∠ACE+∠ABE=90°.
(1)如图1,当
=60°时,线段BD与CE的数量关系为 ,线段EA,EB,EC的数量关系为 ;
(2)如图2当
=90°时,请写出线段EA,EB,EC的数量关系,并说明理由;
(3)在(2)的条件下,当点E在线段CD上时,若BC=
,请直接写出△BDE的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
(1)如图1,当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
(2)如图2当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
(3)在(2)的条件下,当点E在线段CD上时,若BC=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03e9d0e63d7ec8ddf95482bf0bc5b144.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/8/e31638d3-ccaf-4d3f-a2c2-a8179a7e5eb0.png?resizew=494)
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【推荐2】如图,等边△ABC中,点D、E分别在边BC、AC上,∠ADE=60°.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/20/5d47450f-6943-43c4-b6e8-bbb16bdd0929.png?resizew=143)
(1)求证:△ABD∽△DCE;
(2)若BD=2,CE=
,求等边△ABC的边长.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/20/5d47450f-6943-43c4-b6e8-bbb16bdd0929.png?resizew=143)
(1)求证:△ABD∽△DCE;
(2)若BD=2,CE=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d599cb4a589f90b0205f24c2e1fa021e.png)
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