英和和英

出典:『Wikipedia』 (2011/06/15 23:15 UTC 版)

英語による解説

引用

In Euclidean geometry, a eutactic star is a geometrical figure in a Euclidean space. A star is a figure consisting of any number of opposing pairs of vectors (or arms) issuing from a central origin. A star is eutactic if it is the orthogonal projection of a cross-polytope from a higher-dimensional space onto a subspace. Such stars were "eutactic" – meaning "well-situated" or "well-arranged" – by , p. 134) because, for a common scalar multiple, their vectors are projections of an orthonormal basis.