I am wrong in thinking the circumference or the diameter of a circle has to be rational?

  • Alteon@lemmy.world
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    8 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’s diameter, it WILL take 3.14 lengths of string to wrap around the circle (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 rational numbers at the same time. Either your Diameter is a rational 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)

      • Alteon@lemmy.world
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        8 months ago

        *rational

        Good catch. Fixed. I apparently suck with words sometimes. Intent good. Execution flawed. :)

    • elbowgrease@lemm.ee
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      8 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!

    • SkyezOpen@lemmy.world
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      8 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?

        • SkyezOpen@lemmy.world
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          8 months ago

          Right, so you’d need 3.14 strings of length D to cover the circle, D wouldn’t wrap around it itself.

          • Alteon@lemmy.world
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            8 months ago

            It was implied that it would wrap around the circle. I’ll update original post to clarify better.

            • SkyezOpen@lemmy.world
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              8 months ago

              Yeah that’s what I gathered, but it’s backwards. C = Pi D means you need pi strings, not that it’ll cover the circle pi times.

              • Alteon@lemmy.world
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                8 months ago

                Ahhhh. I see what your saying. It’s fixed.

                Yeah. Did not mean to intend that it wraps fully around the circle pi times. Good catch.