7年级上册数学角平分线的有关计算（英语表达七年级数学）

老大TONY的数学笔记

请读懂下面英文？

how to bisect an angel by one compass？

how to bisect an angel requires one compass setting and three arcs

we're expecting to cut this angel in half here

The first need to do as you take your campass with this needle and you place it on the vertex of the angel

open up your compass to a comfortable length that works for you

you are gonna strike an arc through both sides of the angel

you can change the setting if you want.but it has to be the exact same settings of the first arc.

you could have whatever setting you want as long as you go through both sides for the next to arcs and has to be the exact same setting

i'm strike an arc out here so that crosses through the center the interior of this angle here

then i'm going to put the needle on the other original intersection I had, make another arc

here where it intersects the first mark.

after that that intersection you need to take straight edge

you can create a ray or a line segment drawn through the vertex of the original angle through the intersection of those two arcs

and then you have yourself an angle bisector

看中文说英文：

如何通过圆规来平分一个角？

平分一个角需要一个圆规，再做三条弧线。

我们想要平分这个角。

首先你要把你的圆规用针尖儿来对准这个角的顶点。

打开你的圆规到一个合适的长度，你要用这个长度来工作。

你要画一个弧通过这个角的两边，

你也可以改变你的设置。但是注意第二个弧线角度必须和第一个一样。

你可以选用你喜欢的任何设置。只要两次通过角边边的弧时圆规设置是一样的。

我现在在画一个弧线它可以通过这个角的中心区域。（此处省略圆规的针尖位置，针尖的位置应该位于。第一个圆弧和角边长的交点处）

然后再把中间放到另一个交点处，再做一个相同的弧。

他们相交在一个交点。

在交点处你可以做一条直线。

你可以做一条射线或者是线段。通过顶点和两个弧线的交点。

然后你就有你自己的角平分线了。

答案：

how to bisect an angel by one compass？ 如何通过圆规来平分一个角？

how to bisect an angel requires one compass setting and three arcs 平分一个角需要一个圆规，再做三条弧线。

we're expecting to cut this angel in half here 我们想要平分这个角。

The first need to do as you take your campass with this needle and you place it on the vertex of the angel 首先你要把你的圆规用针尖儿来对准这个角的顶点。

open up your compass to a comfortable length that works for you 打开你的圆规到一个合适的长度，你要用这个长度来工作。

you are gonna strike an arc through both sides of the angel 你要画一个弧通过这个角的两边，

you can change the setting if you want.but it has to be the exact same settings of the first arc. 你也可以改变你的设置。但是注意第二个弧线角度必须和第一个一样。

you could have whatever setting you want as long as you go through both sides for the next to arcs and has to be the exact same setting 你可以选用你喜欢的任何设置。只要两次通过角边边的弧时圆规设置是一样的。

i'm strike an arc out here so that crosses through the center the interior of this angle here 我现在在画一个弧线它可以通过这个角的中心区域。（此处省略圆规的针尖位置，针尖的位置应该位于。第一个圆弧和角边长的交点处）

then i'm going to put the needle on the other original intersection I had, make another arc 然后再把中间放到另一个交点处，再做一个相同的弧。

here where it intersects the first mark. 他们相交在一个交点。

after that that intersection you need to take straight edge 在交点处你可以做一条直线。

you can create a ray or a line segment drawn through the vertex of the original angle through the intersection of those two arcs 你可以做一条射线或者是线段。通过顶点和两个弧线的交点。

and then you have yourself an angle bisector 然后你就有你自己的角平分线了。

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