Geometic Series that sums to circle?

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    Circle Series Sums
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Discussion Overview

The discussion revolves around the possibility of dividing the area of a circle using similar polygons with a common ratio, exploring whether this can be represented as a geometric series. Participants consider both theoretical implications and practical constructions related to this concept.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant inquires about the feasibility of dividing a circle's area into similar polygons with a common ratio, noting an attempt to inscribe a square and create triangles, but finding no common ratio among the triangles.
  • Another participant proposes that if the area of the unit disk can be expressed as a limit of a geometric series, it would lead to a specific equation involving the area and a constant ratio, suggesting that this implies irrationality in either the area or the ratio.
  • A different participant points out the formula for the area of a circle, questioning why the presence of irrational numbers would detract from the attractiveness of the geometric series approach.
  • One participant clarifies their focus on the unit disk and acknowledges the possibility of using irrational ratios, but expresses that constructing such numbers is generally more complex than using rational ones.

Areas of Agreement / Disagreement

Participants express differing views on the implications of using irrational numbers in the context of geometric series and the division of a circle's area. There is no consensus on whether this approach is feasible or attractive.

Contextual Notes

Participants discuss the limitations of using rational versus irrational numbers in the context of geometric series, but do not resolve the implications of these choices on the overall feasibility of the proposed method.

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Does anyone know if there is a way to divide up the area of a circle using similar polygons, with a common ratio? I was just curious if there is a way, or if it has been proven impossible.

For example, I tried inscribing a square inside a circle and making an infinite series of triangles with the remaining area, but the triangles do not have a common ratio.
 
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IF we can write the area of the unit disk as the limit of a geometric series, then, with a0 being the area of the largest sub-figure, and k the constant ratio, then we would necessarily have the following equation:

\frac{a_{0}}{1-k}=\pi

But, since the ratio between rational numbers itself must be rational, it follows that either a0, k, or both must be irrational numbers.

And that sort of deflates the attractiveness of the procedure, don't you agree?
 
This probably doesn't make a difference but the area of circle is equal to pi*r^2 where r is the radius of the circle.

But I don't know why that would deflate the attractiveness of the procedure. Why couldn't the ratio be the sqrt(2) or something?
 
I was talking about the "unit disk", with radius equal to 1.

Well, sure it could be 1/square root of two or whatever else, but to construct some nasty irrational number is generally more difficult than a simple rational ratio.
 

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