Let a cyclic polygon be triangulated in any manner by non-intersecting diagonals. Prove that the sum of the inradii of the triangles formed is a constant independent of the triangulation chosen (invariant).
Reference: Weisstein, Eric W. "Japanese Theorem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/JapaneseTheorem.html
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Ten problems: 1411-1420
Incenter, Inradius, Inradii
Sangaku Japanese Geometry
HTML5 and Dynamic Geometry
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