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Article
Triangles and Groups via Cevians
Journal of Geometry
  • Árpád Bényi, Western Washington University
  • Branko Ćurgus, Western Washington University
Document Type
Article
Publication Date
1-1-2012
Keywords
  • Brocard angle,
  • Median triangle,
  • Generalized median triangle,
  • Cevian,
  • Left-circulant matrix,
  • Reflection matrix
Disciplines
Abstract

For a given triangle T and a real number ρ we define Ceva’s triangle Cρ(T) to be the triangle formed by three cevians each joining a vertex of T to the point which divides the opposite side in the ratioρ: (1 – ρ). We identify the smallest interval MT⊂R such that the family Cρ(T),ρ∈MT, contains all Ceva’s triangles up to similarity. We prove that the composition of operators Cρ,ρ∈R, acting on triangles is governed by a certain group structure on R. We use this structure to prove that two triangles have the same Brocard angle if and only if a congruent copy of one of them can be recovered by sufficiently many iterations of two operators Cρ and Cξ acting on the other triangle.

DOI
http://dx.doi.org/10.1007/s00022-013-0142-x
Subjects - Topical (LCSH)
Triangle
Genre/Form
articles
Type
Text
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.
Language
English
Format
application/pdf
Citation Information
Árpád Bényi and Branko Ćurgus. "Triangles and Groups via Cevians" Journal of Geometry Vol. 103 Iss. 3 (2012) p. 375 - 408
Available at: http://works.bepress.com/branko_curgus/8/