如图,
是
的高,
垂直平分线分别交
,
,
于点
,
,H.连接
,
.
;
(2)若
,求
的长.
![](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/03902478df1a55bc99703210bccab910.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/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/235efb0966d2d2342357833ee4cc0a58.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82773737609e65dea3c5c67099f1b10d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
更新时间:2024-05-07 21:57:44
|
相似题推荐
解答题-证明题
|
适中
(0.65)
【推荐1】在三角形ABC中,点D在线段AB上,DE∥BC交AC于点E,点F在直线BC上,作直线EF,过点D作直线DH∥AC交直线EF于点H.
![](https://img.xkw.com/dksih/QBM/2021/7/9/2760281588006912/2817079387742208/STEM/45a3bc6e-4dcf-4135-bdbd-e1242d9f0583.png)
(1)在如图1所示的情况下,求证:∠HDE=∠C;
(2)若三角形ABC保持不变,D,E两点的位置也不变,点F在直线BC上运动.
①当点H在三角形ABC内部时,试说明∠DHF与∠FEC的数量关系;
②当点H在三角形ABC外部时,①中结论是否仍然成立?若不成立,∠DHF与∠FEC又有怎样的数量关系?请在备用图中画图探究,并说明理由.
![](https://img.xkw.com/dksih/QBM/2021/7/9/2760281588006912/2817079387742208/STEM/45a3bc6e-4dcf-4135-bdbd-e1242d9f0583.png)
(1)在如图1所示的情况下,求证:∠HDE=∠C;
(2)若三角形ABC保持不变,D,E两点的位置也不变,点F在直线BC上运动.
①当点H在三角形ABC内部时,试说明∠DHF与∠FEC的数量关系;
②当点H在三角形ABC外部时,①中结论是否仍然成立?若不成立,∠DHF与∠FEC又有怎样的数量关系?请在备用图中画图探究,并说明理由.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】已知:如图所示,
,
,求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2e8e59609f1c42d1aff0008ec23f31e.png)
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963669874335744/3060658537406464/STEM/829bb45b05d640c4b408d651d1f2affc.png?resizew=185)
完成下面的证明:
证明:∵
(已知),
∴
_______( ),
∴
( ).
又∵
( ),
∴
________( ),
∴
( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3e2d131cf4bd2f1aa71bcd23bf96534.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2e8e59609f1c42d1aff0008ec23f31e.png)
![](https://img.xkw.com/dksih/QBM/2022/4/22/2963669874335744/3060658537406464/STEM/829bb45b05d640c4b408d651d1f2affc.png?resizew=185)
完成下面的证明:
证明:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e53497af8899cb299d762f1a4f46a55.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68fdb2b9d6a4a54ed1328c5b3adcf7b6.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37cea15ea22cc4fc17c8b35eede09e42.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3e2d131cf4bd2f1aa71bcd23bf96534.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5324ce5fd43c5b05e8fad764880f7b3.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2e8e59609f1c42d1aff0008ec23f31e.png)
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解答题-问答题
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适中
(0.65)
【推荐1】如图,在
中,
,点D是
的中点.
求证:
.
下面是两位同学两种添加辅助线的方法:
请选择一位同学的方法,完成证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3262fc038bbec5e7c8cc47df08bef7.png)
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![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/8/94aaff98-d28f-49c3-a32e-d5e494ccccd4.png?resizew=128)
求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c71622531dfa894f21b2da123d020d24.png)
下面是两位同学两种添加辅助线的方法:
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/8/0c926639-efa5-45a9-8a6b-353ce4ba3c12.png?resizew=438)
请选择一位同学的方法,完成证明.
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解答题-作图题
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适中
(0.65)
【推荐2】如图,AC是平行四边形ABCD的对角线.
(1)利用尺规作出AC的垂直平分线(要求保留作图痕迹,不写作法);
(2)设AC的垂直平分线分别与AB,AC,CD交于点E,O,F,求证:以A、E、C、F为顶点的四边形为菱形.
(1)利用尺规作出AC的垂直平分线(要求保留作图痕迹,不写作法);
(2)设AC的垂直平分线分别与AB,AC,CD交于点E,O,F,求证:以A、E、C、F为顶点的四边形为菱形.
![](https://img.xkw.com/dksih/QBM/2019/8/12/2267160115814400/2268106341433344/STEM/f5d454658de74f799e624b6fcc8d6eab.png?resizew=179)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
【推荐1】已知:如图,在平行四边形
中,
与
的角平分线的交点
恰好在边
上,延长
交
的延长线交于点
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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解答题-证明题
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适中
(0.65)
【推荐2】如图:已知AD平分∠BAC,∠B+∠C=180°
![](https://img.xkw.com/dksih/QBM/2019/10/23/2318135231037440/2320426949623808/STEM/c4a403c92b18488bb4184b2f0202de99.png?resizew=427)
(1)如图①,当∠B=90°时,求证:DB=DC;
(2)如图②,如果∠ABD<90°时,(1)中的结论还成立吗?如果成立,请给出证明,如果不成立,请举反例说明;
(3)如图③,四边形ABDC中,∠B=45°,∠C=135°,DB=DC=1,则AB−AC=___.
![](https://img.xkw.com/dksih/QBM/2019/10/23/2318135231037440/2320426949623808/STEM/c4a403c92b18488bb4184b2f0202de99.png?resizew=427)
(1)如图①,当∠B=90°时,求证:DB=DC;
(2)如图②,如果∠ABD<90°时,(1)中的结论还成立吗?如果成立,请给出证明,如果不成立,请举反例说明;
(3)如图③,四边形ABDC中,∠B=45°,∠C=135°,DB=DC=1,则AB−AC=___.
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