By projecting a straight line on a plane orthogonal projection, its projection, generally, is smaller than the original measure.
Given a straight (segment bounded by two points) we want to determine its true magnitude and the angle it makes with the planes of projection.
The main projections on two planes straight dihedral (horizontal and vertical planes) possible to determine other new planes orthogonal projections on.
We'll see how generically determine a new projection from two. Later we will consider your application to study the so-called “auxiliary projections”, influencing their usefulness in solving various problems.
After seeing the foundations of Diédrico System, with the projection of a point on two planes orthogonal projection, let's see how you can wean the system of land line as we have two or more points. This system called “Free System” is more flexible than the traditional because Monge, giving prominence to the reference lines and guiding the conceptual model to a more constructive and less spatial geometry.
We have seen in presenting Representation Systems descriptive geometry that is the set of techniques that allows to represent geometric character three dimensional space on a two dimensional surface.
In particular we explore in detail the so-called “System dihedral” based on the prospects ratios appearing in the cylindrical projection on two planes orthogonal projection.
