202207学习

佳创兴2015 · 发表于 2022-7-2 00:16:03

a.
为了求一个角的弧度，以这个角的顶点为圆心，作半径为1的圆，  这个角切割圆周一段弧，弧的长度，是这角的弧度。
   (我们就定义这段弧的长度为该角的弧度)
   若是个360°的角，弧长就是整个圆周，(圆半径为1)，弧度就是2π .

b.
圆心角，切割圆周，一段弧, 弧长l
圆的半径R, 圆心角n°
l= n/360 * 2πR

又有
l/R=(n/360)*2π

c.
1弧度= 180/π  (度)

迷茫的维修 · 发表于 2022-7-2 06:27:07

加油，

佳创兴2015 · 发表于 2022-7-2 22:23:03

7.2 practice English

佳创兴2015 · 发表于 2022-7-3 21:12:52

弧度制弧度、角度、半径、弧长

佳创兴2015 · 发表于 2022-7-4 21:23:27

Which stop should I get off at? You can buy a ticket from the ticket machine .

佳创兴2015 · 发表于 2022-7-6 07:45:08

测量，显卡电路，测对地阻值

佳创兴2015 · 发表于 2022-7-11 05:39:37

7.10 It's too cold to eat ice crem. It's too late for me to drink coffee . I wouldn't sleep tonight.

佳创兴2015 · 发表于 2022-7-11 21:58:28

7.11
This is a subway line.
This is a ticket machine.
A oyter card
The oldest subway, London subway.

佳创兴2015 · 发表于 2022-7-14 22:30:42

Learning English.
   When we came out of the exit of the Shopping mall .
   We were next to the square.
   The subway entrance shouldn't  too far.

佳创兴2015 · 发表于 2022-7-17 22:41:00

They are looking forward to summer vacation.

		自动登录	找回密码
密码			立即注册