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A188616
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Decimal expansion of angle B of unique side-golden and angle-silver triangle.
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2
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5, 9, 1, 0, 6, 7, 7, 9, 9, 7, 0, 5, 1, 6, 4, 8, 7, 9, 7, 6, 3, 2, 3, 2, 3, 7, 4, 1, 9, 6, 6, 2, 1, 7, 2, 3, 6, 0, 5, 4, 9, 7, 8, 5, 3, 1, 4, 6, 5, 8, 3, 4, 0, 5, 9, 0, 5, 0, 3, 1, 3, 2, 9, 0, 3, 6, 5, 9, 4, 6, 1, 4, 7, 0, 8, 5, 5, 8, 0, 0, 1, 2, 5, 4, 3, 4, 3, 8, 2, 2, 5, 8, 1, 9, 1, 6, 4, 3, 1, 2, 6, 6, 0, 3, 6, 8, 6, 5, 6, 4, 1, 3, 8, 1, 5, 7, 7, 8, 3, 7
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OFFSET
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0,1
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COMMENTS
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Let r=(golden ratio)=(1+sqrt(5))/2 and u=(silver ratio)=1+sqrt(2). A triangle ABC with sidelengths a,b,c is side-golden if a/b=r and angle-silver if C/B=u. There is a unique triangle that has both properties. The quickest way to understand the geometric reasons for the names is by analogy to the golden and silver rectangles. For the former, exactly 1 square is available at each stage of the partitioning of the rectangle into a nest of squares, and for the former, exactly 2 squares are available. Analogously, for ABC, exactly one 1 triangle of a certain kind is available at each stage of a side-partitioning procedure, and exactly 2 triangles of another kind are available for angle-partitioning. For details, see the 2007 reference.
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LINKS
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EXAMPLE
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B=0.59106779970516487976323237419662 approximately
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MATHEMATICA
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Remove["Global`*"]; r=1+2^(1/2); u=(1+5^(1/2))/2; RealDigits[FindRoot[Sin[r*t+t]==u*Sin[t], {t, 1}, WorkingPrecision->120][[1, 2]]][[1]]
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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