ABSTRACT
To introduce methods of constructing drawings of two types – orthographic projection and isometric drawings.
Orthographic projection involves viewing an article being described in a technical drawing from different directions – from the front, from a side, from above, from below or from any other viewing position. Orthographic projection often involves: 1. The drawing of details which are hidden, using hidden detail lines; 2. Sectional views in which the article being drawn is imagined as being
cut through and the cut surface drawn; 3. Centre lines through arcs, circles, spheres and cylindrical shapes.
