Projections of Straight Lines

Chapter - 12

Projections of Straight Lines

At the end of this chapter we will be able to:

1. List out the possible positions of straightline in Dihedral angles. 

2. Draw the projections of straightlines, located in First Quadrant, 

a) parallel to both the reference planes.

b) parallel to one plane and perpendicular to the other plane, as

i) Parallel to HP & Perpendicular to VP.

ii) Parallel to VP & Perpendicular to HP.

c) parallel to one plane and inclined to the other plane, as

i) Parallel to HP & Inclined to VP.

ii) Parallel to VP & Inclined to HP.

d) inclined to both the reference planes.

3. Determine the true length and true inclinations of straight lines for different positions.

4. Draw the traces of straightlines for its different positions.

INTRODUCTION

Orthographic projections of points with various positions in Dihedral angles are given in the last chapter. By joining more number of points which are placed at closer interval in a specified direction, a line is obtained. Orthographic projections of straight lines is presented in this chapter.

A straight line may be defined as the locus of a point which moves along the shortest path joining two given points. A straight line may also be defined as the locus of a point which moves linearly. Thus two ends of a straight line are points. Therefore projection of a straight line can be drawn by joining the respective projections of its end points.

A line in this chapter is considered to be a straight line unless the shape is specified.