About the determination of the center and axis of a direct similarity in 3D
ISSN: 1135-0261
Ano de publicación: 2019
Título do exemplar: Profesor Joaquín Hernández Gómez
Número: 108
Páxinas: 57-72
Tipo: Artigo
Outras publicacións en: Boletín de la Sociedad Puig Adam de profesores de matemáticas
Resumo
A 3D direct similarity defined by a tetrahedron and its image tetrahedron of proportional edges is considered. This similarity is a "dilative rotation", consisting of a rotation around an axis and a stretch with center in the rotation axis. Methods of synthetic geometry are used in this paper for determining such center and axis. Finally, methods of elementary analytic geometry with matrix calculus are used for solving concrete examples in a brief way.