如图1,∠AOB是平角,∠COD是直角,射线OB在∠COD内部,OE,OF分别是∠BOD,∠AOC的平分线.
![](https://img.xkw.com/dksih/QBM/2022/1/20/2898270857428992/2917670028288000/STEM/5b81f3bb-533a-4681-b23c-35a58694fb08.png?resizew=368)
(1)如图1,若OB是∠COD的平分线,求∠AOF的度数;
(2)如图1,求∠EOF的度数;
(3)若改变∠COD的位置变化,如图2,当∠COD在直线AB的上方时,如图3,当射线OA在∠COD内部时,如图4,当∠COD在直线AB的下方时,∠EOF的度数发生变化吗?若不变,请直接写出∠EOF的度数;若不确定,请说明理由.
![](https://img.xkw.com/dksih/QBM/2022/1/20/2898270857428992/2917670028288000/STEM/5b81f3bb-533a-4681-b23c-35a58694fb08.png?resizew=368)
(1)如图1,若OB是∠COD的平分线,求∠AOF的度数;
(2)如图1,求∠EOF的度数;
(3)若改变∠COD的位置变化,如图2,当∠COD在直线AB的上方时,如图3,当射线OA在∠COD内部时,如图4,当∠COD在直线AB的下方时,∠EOF的度数发生变化吗?若不变,请直接写出∠EOF的度数;若不确定,请说明理由.
更新时间:2022-02-16 15:17:46
|
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】点O为直线
上一点,过点O作射线
,使
,将一直角板的直角顶点放在点O处.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/20/50b1ed15-7522-4f91-9125-f3f49cb1e159.png?resizew=344)
(1)如图1,将三角板
的一边
与射线
重合时,则
______°;
(2)如图2,将三角板
绕点O逆时针旋转一定角度,此时
是
的角平分线,求旋转角
和
的度数;
(3)将三角板
绕点O逆时针旋转过程中,当
时,直接写出
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1317a678bfc84025377e617df06df25.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/20/50b1ed15-7522-4f91-9125-f3f49cb1e159.png?resizew=344)
(1)如图1,将三角板
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1eb76f88cb973c220cffa1c9c0721a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88e9f7d1272b7344346b58b660aa260a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147eae0623b2455cb5afc132f614fca8.png)
(2)如图2,将三角板
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1eb76f88cb973c220cffa1c9c0721a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77603496a315e39db671c0c1e4256cc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b2f7bab4ed36ec5d04db3aeed2796f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6463e5b629f54a517050d1327580aa5b.png)
(3)将三角板
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1eb76f88cb973c220cffa1c9c0721a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae12c0bd87f76983be1e4c55bf4c96fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32a89a0850a156bef223fba4d9609156.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,将一副三角板的两个直角顶点O重合在一起,放置成如图所示的位置.
(1)如图1,若
,猜想
______;
(2)小明推测:三角板
绕重合的点O旋转(三角板
保持不动),不论转动到哪个位置,“
与
始终互补”,你同意他的结论吗?请说明理由.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/19/3b8e715e-5aa4-4ff1-82a6-9fddd889698a.png?resizew=394)
(1)如图1,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db91877e869a8d58b2bab2c39756d7fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66b05714b8620eba2f56084a91442533.png)
(2)小明推测:三角板
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3201d3796ed9a29338aac25245a7c8e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4819c39c281427826e1b3f7a4c2b720.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e7b8a59f8d66176463f3d71f882a26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d22df2977de56cc69be0c1e847653d7a.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐1】如图所示,∠AOB是平角,OM、ON分别是∠AOC、∠BOD 的平分线.
(1)知∠AOC=40°,∠BOD=60°,求∠MON的度数;
(2)知∠COD=90°,求出∠MON的度数.
(1)知∠AOC=40°,∠BOD=60°,求∠MON的度数;
(2)知∠COD=90°,求出∠MON的度数.
![](https://img.xkw.com/dksih/QBM/2018/1/19/1863631091441664/1865269016985600/STEM/d1c055ac98244f3181e42b2ec0993f0d.png?resizew=195)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】已知:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d47544762477a667f37ea4e5310b956.png)
(1)如图1,
吗?请说明理由.
(2)如图2,直线
平分
,直线
平分
吗?请说明理由.
(3)若
,
,求
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d47544762477a667f37ea4e5310b956.png)
(1)如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3da02b38bc1ab163a7471711b9b1427e.png)
(2)如图2,直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e7b8a59f8d66176463f3d71f882a26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d22df2977de56cc69be0c1e847653d7a.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f9364e35182c3dcae4a4f13ad7088fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5d76e473d7adc43014cd22032a84f41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75f55c6ac896ab4277fae2230a6e10b0.png)
![](https://img.xkw.com/dksih/QBM/2021/2/7/2653007807619072/2663372549955584/STEM/ffbe275a-65a6-488a-a781-c520d4eae76c.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,已知
,
.
.请将下面证明过程补充完整:
证明:∵
(已知)
∴
(①____________)
又∵
(已知)
∴②_____________(③____________)
∴
(④_____________)
∴
(两直线平行;同位角相等)
(2)若
平分
,
于点E,
,求
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec5048da25cfba78c683d4dec68f0771.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d1717b5311ed602f1730e86d9322647.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff048fcb7321f68dac61d679d4314992.png)
证明:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12a11be1dce47ca9df1e6999b55c4917.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e20360cd68f0e77a3f0ca955a547be9.png)
又∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d1717b5311ed602f1730e86d9322647.png)
∴②_____________(③____________)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11746407732cc6c2332a6ef126e9f952.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff048fcb7321f68dac61d679d4314992.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d598f4a17ac14970ade9f381e9aee970.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc3a3137299ffaea0545cd45323f1af2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41f5447fb38f69a45b641a373f7c7df3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727ad3e630a224303d6d3b8ad5c114ba.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】如图,直线AB、CD相交于点O,OE平分∠AOD,OF⊥OC,∠3=65°,求∠1与∠2的度数.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/18/95c6db25-f214-470a-a292-5394d2bb28a5.png?resizew=198)
您最近一年使用:0次