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In geometry, the snub dodecadodecahedron is a nonconvex uniform polyhedron, indexed as U40. It is given a Schläfli symbol sr, as a snub great dodecahedron. == Cartesian coordinates == Cartesian coordinates for the vertices of a snub dodecadodecahedron are all the even permutations of : (±2α, ±2, ±2β), : (±(α+β/τ+τ), ±(-ατ+β+1/τ), ±(α/τ+βτ-1)), : (±(-α/τ+βτ+1), ±(-α+β/τ-τ), ±(ατ+β-1/τ)), : (±(-α/τ+βτ-1), ±(α-β/τ-τ), ±(ατ+β+1/τ)) and : (±(α+β/τ-τ), ±(ατ-β+1/τ), ±(α/τ+βτ+1)), with an even number of plus signs, where : β = (α2/τ+τ)/(ατ−1/τ), where τ = (1+√5)/2 is the golden mean and α is the positive real root of τα4−α3+2α2−α−1/τ, or approximately 0.7964421. Taking the odd permutations of the above coordinates with an odd number of plus signs gives another form, the enantiomorph of the other one. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Snub dodecadodecahedron」の詳細全文を読む スポンサード リンク
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