Szeredi, Éva2024-09-042024-09-042012-06-01Teaching Mathematics and Computer Science, Vol. 10 No. 1 (2012) , 1-121589-7389https://hdl.handle.net/2437/379711This paper is a continuation of the article Forming the concept of congruence I., where I gave theoretical background to the topic, description of the traditional method of representing the isometries of the plane with its effect on the evolution of congruence concept. In this paper I describe a new method of representing the isometries of the plane. This method is closer to the abstract idea of 3-dimensional motion. The planar isometries are considered as restrictions of 3-dimensional motions and these are represented with free translocations given by flags. About the terminology: I use some important concepts connected to teaching of congruence, which have to be distinguished. My goal is to analyse different teaching methods of the 2-dimensional congruencies. I use the term 3-dimensional motion for the orientation preserving (direct) 3-dimensional isometry (which is also called rigid motion or rigid body move). When referring the concrete manipulative representation of the planar congruencies I will use the term translocation.application/pdfteacher educationconcept formationacquisition of mathematical conceptstransformation geometrymanipulative materialsteaching methods and classroom techniquesfolyóiratcikkOpen AccessÉva Szeredihttps://doi.org/10.5485/TMCS.2012.0248Teaching Mathematics and Computer Science110Teach. Math. Comp. Sci.2676-8364