如图,∠MON=90°,点A,B分别在射线OM,ON上移动,∠OAB的平分线与∠OBA的外角平分线交于点C,试猜想:随着点A,B的移动,∠ACB的大小是否发生变化,并说明理由.
![](https://img.xkw.com/dksih/QBM/2018/8/24/2017236558807040/2018246812147712/STEM/86f9ec7c173d4de2a27c1120192bc688.png?resizew=139)
更新时间:2018-08-25 21:16:33
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【知识点】 与角平分线有关的三角形内角和问题解读
相似题推荐
解答题-证明题
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名校
【推荐1】如图,已知:
,
,
平行![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/29/b88cd4c5-496e-4c4d-ab3c-da4f2b90519d.png?resizew=149)
(1)求证:
平分
.
(2)直接写出图中是
度数2倍的角
(3)如果
,
,求
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1598ad60d36f87f7fed1a58cf5c2c42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c85f161105fa2dbed7f41a059b348a07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/29/b88cd4c5-496e-4c4d-ab3c-da4f2b90519d.png?resizew=149)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fabb884dc5f9609de491245463bbe9a.png)
(2)直接写出图中是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d57899ad4774aed9ccc7bd23db72153.png)
(3)如果
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b757f0c42ae5c9a2d6a4b19e5877b27.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a5cd516a35c424b5c17bb25f85ae84c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/605f2976297a0deaa1602ef09d6a5afa.png)
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【推荐2】如图①,线段
,
相交于点
.
(1)求证:
;
(2)如图②,线段线段
,
相交于点
,
和
的角平分线相交于点
,
,
相交于点
,
,
相交于点
,若
,
,请结合(1)中的结论,求
的度数.
![](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/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/29/f4e24b62-9f7d-4202-a123-98f10c693e5f.png?resizew=266)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9d0a0a22737590ac049c49da6de2c38.png)
(2)如图②,线段线段
![](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/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdb8eca20ce2c918ea4034ea15210c7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a9fe609f7851c20ad9a6892f080a0ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](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/ac047e91852b91af639feec23a9598b2.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/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d777d15cd733338ecfd0ea63819f62c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/691048ce61c91a8a3680fa3025193160.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b871a762469393cdd22f15aa49ebb8f9.png)
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【推荐3】阅读下列材料并解答问题:
在一个三角形中,如果一个内角
的度数是另一个内角度数的
倍,那么这样的三角形我们称为
特征三角形
,其中
称为
特征角
例如:一个三角形三个内角的度数分别是
、
、
,这个三角形就是
特征三角形
,其中
特征角
为
.反之,若一个三角形是“特征三角形”,那么这个三角形的三个内角中一定有一个内角
的度数是另一个内角度数的
倍.
,若“特征角”为锐角,则这个“特征角”的度数为
.
(2)如图1,
中,点
在边
上,
平分
交
于点
.
①若
,
,判断
是否为“特征三角形”,并说明理由;
②若
,
是“特征三角形”,请直接写出
的度数;
③如图2,若
为线段
上一点,且
+
,
.若
是“特征三角形”,求
的度数.
在一个三角形中,如果一个内角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fed15b57f7dcae3668a9dbbaca904af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ca7514754bba83b1ee7565391a6b3c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fed15b57f7dcae3668a9dbbaca904af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ca7514754bba83b1ee7565391a6b3c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e3b753ad06d7e5a41d809c8d32552e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eb90b8c8cadeb19eaf4e2abec1ab413.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c030b25575d683af91c06e6a3e4f463.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fed15b57f7dcae3668a9dbbaca904af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ca7514754bba83b1ee7565391a6b3c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fed15b57f7dcae3668a9dbbaca904af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ca7514754bba83b1ee7565391a6b3c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e3b753ad06d7e5a41d809c8d32552e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84288b493b64c3a30466fb9075621da4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83873a9d782f2588c5eedbfe73f9bc2f.png)
(2)如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a6c6e7c025362c46a64a8956761f08e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/066c7fd724932eef6a43ec951f17981c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8648cc68448cb78e36cff296b912ea46.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a20e5d585fbf903ee5affa6d083ab95f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82fe5c73d09889ebd16037f4779a1046.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7df46ad76c129a1eccdea3553e0b7423.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82fe5c73d09889ebd16037f4779a1046.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b69923f7d2733e929c02575e7eed623.png)
③如图2,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88929f4ba0851730d5f941d426b87548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4974a9f7f0c6dee5ab3cdab6bba5b780.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baa916895c648a435a323134353fea13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3260ba3881df0ad2fd4b43c440155380.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e75fb6f9ad72dea327a6895915cd5355.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e8f6faf46c448fe8d838fde1af495b.png)
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