Radius from arc length and central angle

[JSmith]

If the central angle is

radians, what should the radius of a circle be to make the arc length 1 m?
So... then 4pi/3 is 2/3 of a circle... then the complete arc length would be 1.5... then 2pir=1.5, r=1.5/2pi = 0.477.

Am I doing this right?

 

[srmichael]

If the central angle is

radians, what should the radius of a circle be to make the arc length 1 m?
So... then 4pi/3 is 2/3 of a circle... then the complete arc length would be 1.5... then 2pir=1.5, r=1.5/2pi = 0.477.

Am I doing this right?

Except 1.5/(2π) = 0.239, not 0.477.

I prefer to do it this way:

s = arc length

s = rΘ

1 = r[(4π)/3]

r = 1/[(4π)/3] = 3/(4π) = 0.239

 

[srmichael]

"Why are boxing rings square?"

Why do we park in driveways and drive on parkways?

Why did one house go up in smoke while another went down in smoke?
​

Why does Hawaii have interstates?

When you see a fly on the ciling was it flying upside down the entire time or did it flip upside down right at the last moment?

 

[lookagain]

I don't know how/why this thread got hijacked.


I saw a sign on a road that reads "hidden driveway" (presumably ahead a short distance).
If the driveway is hidden, what good does it for drivers to see this sign, because they won't know where the driveway is?

I saw a traffic sign with a blue background, a white question mark on it, and an arrow underneath it pointing to the left.
How is this going to help me when the people who put up the sign don't know what's over there?

A teacher asked Johnny, "Johnny, what is the solution to this matchstick puzzle? Johnny said, "Well, if you don't
know, how would you expect me to figure it out!?"

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