Maths Olympiad Prep

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Geometry Difficulty 5.9 AIME, harder Prove it Belarus

A circle ω\omega of radius 11 is given. A collection TT of triangles is called good, if the following conditions hold:
(i) each triangle from TT is inscribed in ω\omega;
(ii) no two triangles from TT have a common interior point.
Determine all positive real numbers tt such that, for each positive integer nn there exist a good collection of nn triangles, each of perimeter greater than tt.

Solution

1. See IMO-2018 Shortlist, Problem G3.

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