TEACHING DESCRIPTIVE GEOMETRY – CONSTRUCTING AND DEVELOPING THE SURFACES OF SOLIDS

• Published in: JIDEG Vol. 14; no. 1; pp. 277 - 280
• Main Author: Clinciu, Ramona
• Format: Journal Article
• Language: English
• Published: Bucharest Societatea Romana de Grafica Inginereasca (SORGING) 01.05.2019; SORGING
• Subjects: Descriptive geometry; development of the surface; Geometry; method of revolution; Methods; projections; pyramid; solids; Students; Teaching
• ISSN: 1843-3766; 2344-4681

Solids, projections, development of the surface, pyramid, method of revolution. 1.INTRODUCTION The paper presents applications which may be used in teaching descriptive geometry, for the understanding of the principles used for constructing and developing the surfaces of solids. In these conditions, descriptive geometry subject needs to be taught such as to fill the gaps in the knowledge of the students, towards the elements of the plane or spatial geometry and, at the same time, to enable the development of the spatial ability needed for understanding the methods used for constructing the projections of the elements of the plane and spatial geometry and to enable the connection with their spatial shape. Applications are focused on simple solids placed in particular positions and they try to establish the connection between the 3D shape of the solid and its orthogonal projections and, at the same time, they try to help them find the true size of the lengths of the edges needed for developing the surface of the considered solid. According to this method, a side edge of the pyramid which is in a general position - ĮSAI is revolved about an axis of revolution represented by the height of the square | SQ| until it is brought into a position parallel to plane [V] and becomes a vertical line |SE|, its true size being represented by its vertical projection |s'e'|: ||SA|| = ||SE|| = ||s'e'|| (Figure 4 and Figure 5). Since now all needed sizes are known, one can construct the developed surface of the pyramid.