About the determination of the center and axis of a direct similarity in 3D
ISSN: 1135-0261
Année de publication: 2019
Titre de la publication: Profesor Joaquín Hernández Gómez
Número: 108
Pages: 57-72
Type: Article
D'autres publications dans: Boletín de la Sociedad Puig Adam de profesores de matemáticas
Résumé
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.