有两根木条,一根长60cm,一根长100cm,如果将它们放在同一条直线上,并且使一个端点重合,这两根木条中点间的距离是多少?为什么?
更新时间:2019-08-28 08:15:50
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相似题推荐
解答题-作图题
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适中
(0.65)
【推荐1】小东遇到这样一个问题:如图
,有两条线段
,作线段
,求作点
,使点
在线段
的延长线上,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/bf8ed19f-9dc1-4538-81da-3efb520e4134.png?resizew=199)
小东是这样思考的:首先通过分析明确点
在
的延长线上,画出示意图,如图
所示:然后截取
,这时发现
,进而分析要使
,则需
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/f5f1410f-ca37-4740-a45e-ca69eb7d72cb.png?resizew=163)
因此,小东找到了解决问题的方法:延长
到
,并使
,利用直尺找到
的中点
,这样就得到了
.
根据小东的画法我们可知,线段
,点
在线段
的延长线上,且
,点
为
的中点
请你根据以上条件说出
的理由
(2)类比迁移:
①类比小东的画法,由线段迁移到角,完成画图:如图
,
,请画一个
,使
与
互补,要求:保留画图痕迹,并简单叙述画图步骤.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/9a1da2d5-1d58-4e46-a87e-50822c56e8bb.png?resizew=189)
②如图
,已知
和
互补,射线
平分
,射线
平分
.若
,求
的度数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d42e97eee705d164e6ac6de9ecd6d1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88ee3d0cddc5139b6e7c2c011afff116.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/bf8ed19f-9dc1-4538-81da-3efb520e4134.png?resizew=199)
小东是这样思考的:首先通过分析明确点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c52b857c7ca55dfa6da108df1d3cee2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0816b284750cd7bc9dc8d0c892290ba9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88ee3d0cddc5139b6e7c2c011afff116.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a16dc02090b6e9263555061f14fbc8c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/f5f1410f-ca37-4740-a45e-ca69eb7d72cb.png?resizew=163)
因此,小东找到了解决问题的方法:延长
![](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/5c52b857c7ca55dfa6da108df1d3cee2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88ee3d0cddc5139b6e7c2c011afff116.png)
根据小东的画法我们可知,线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d42e97eee705d164e6ac6de9ecd6d1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c52b857c7ca55dfa6da108df1d3cee2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
请你根据以上条件说出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88ee3d0cddc5139b6e7c2c011afff116.png)
(2)类比迁移:
①类比小东的画法,由线段迁移到角,完成画图:如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bb2e3c135325bf8c81fdac69325a7f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba123b68d5eacc7e0f9188df08d7ae0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba123b68d5eacc7e0f9188df08d7ae0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9cd4e42a017412dd69fab0b7a7acd871.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/9a1da2d5-1d58-4e46-a87e-50822c56e8bb.png?resizew=189)
②如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/460893f14dc72e6a6e3db81d754c4f57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df416efbf00259c3b1090cf15c726bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/460893f14dc72e6a6e3db81d754c4f57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8ffe24cf9f327aeb241225ab15ab1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df416efbf00259c3b1090cf15c726bdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4da028073705e0f6a7fda0d4e90bb01a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45a8a837c11c07073da3ff751d70278.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/14/44b3002c-5f96-45f9-b99f-6cc483fc7259.png?resizew=197)
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解答题-问答题
|
适中
(0.65)
【推荐2】(1)如图1,点
在线段
上,
,
,点
,
分别是线段
,
的中点.求线段
的长;
(2)点
在线段
上,若
,点
,
分别是线段
,
的中点.你能得出
的长度吗?并说明理由.
(3)类似的,如图2,
是直角,射线
在
外部,且
是锐角,
是
的平分线,
是
的平分线.当
的大小发生改变时,
的大小也会发生改变吗?为什么?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1af1437fe82b8de117a709e032048f23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af22b8bf00f34f25698ffa5b4ef222dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/3/4a8c5101-71c2-4f08-a572-321ce58de595.png?resizew=389)
(2)点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3be6d6a73601103f6f86923fdc85d59b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
(3)类似的,如图2,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d7b2fe01a33c4825f9974ed9663a99c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fed1f57a835af4e9022e27603d12d31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88e9f7d1272b7344346b58b660aa260a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fed1f57a835af4e9022e27603d12d31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3369e0ea90e8d5cf4b6b3c45c0fd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d22df2977de56cc69be0c1e847653d7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fed1f57a835af4e9022e27603d12d31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27935c1ef4df2d52ac697678a3c8f39d.png)
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