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Comment on Math question: how do we get an irrational number pi from the ratio of circumference and the diameter of a circle?

Alteon@lemmy.world ⁨9⁩ ⁨months⁩ ago

What’s interesting is that no matter how big or how small your circle is, pi is a constant ratio of the diameter to the perimeter (or circumference) of your circle. If you were to cut a string to the length of your circle’ diameter, it WILL ALWAYS wrap around by 3.14159 (or π times). That’s where that number comes from.

Because of this ratio, there will never be a situation in which both the diameter and circumference are both logical numbers at the same time. Either your Diameter is a logical number or your circumference. For example:

P=πD

If D=1… Then P=π(1) or P=π

If P=1… Then P=π(1/π) where D=(1/π)

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elbowgrease@lemm.ee ⁨9⁩ ⁨months⁩ ago
huh - I never thought of it that way but of course it makes total sense.

I love this question - simple but thought provoking!

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amio@kbin.social ⁨9⁩ ⁨months⁩ ago
Logical numbers?

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- Alteon@lemmy.world ⁨9⁩ ⁨months⁩ ago
  *rational
  
  Good catch. Fixed. I apparently suck with words sometimes. Intent good. Execution flawed. :)
  
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SkyezOpen@lemmy.world ⁨9⁩ ⁨months⁩ ago

If you were to cut a string to the length of your circle’ diameter, it WILL ALWAYS wrap around by 3.14159 (or π times).

Isn’t that backwards?

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- Alteon@lemmy.world ⁨9⁩ ⁨months⁩ ago
  Nope.
  
  The equation is P=πD. Meaning the Perimeter is equal to 3.14 times the length of your Diameter.
  
  You can visualize it here: m.youtube.com/watch?v=1lQfERPjkzk
  
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  - SkyezOpen@lemmy.world ⁨9⁩ ⁨months⁩ ago
    Right, so you’d need 3.14 strings of length D to cover the circle, D wouldn’t wrap around it itself.
    
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    Alteon@lemmy.world ⁨9⁩ ⁨months⁩ ago
    It was implied that it would wrap around the circle. I’ll update original post to clarify better.
    
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