The Theory of Orthographic Projection

Projection Box Orthographic Drawing

The fundamental theory is rooted in the principles of solid geometry and need not concern us. The basic idea, so far as drawing is concerned, is that there are three planes mutually at right angles, like the sides of a box. The views are projected onto these planes which are then developed or opened out into a flat sheet - the paper we draw on. In first angle projection, Fig. 89, the object with faces A, B and C visible, is imagined to be suspended inside such a box. Three of the sides are...