User:Gmac4247/basic-geometry/Perimeter of a circle

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Perimeter (circumference) of a circle[edit]

The perimeter (P) of a circle is the difference between the circle and a smaller, concentric circle divided by the difference of the radius of those circles (x).


Note:

 Unwrapping that ring would result in a trapezoid shape, but with just a theoretic height, close to zero. Therefor, it can be regarded as a rectangle.

As x is almost zero, P=6.4r

[1]

References:

  1. ^ Gaál Sándor (2019-01-11). "Basic geometry". Basic geometry. Gaál Sándor.