1. Chapter 4
Auxiliary Views

2. AUXILIARY VIEWS
Inclined planes and oblique lines do not appear true length or true size in any of the principal planes of projection. To determine the true length of an oblique line or the true size of an inclined plane an auxiliary view must be created. With traditional drawing, the view is manually created along line-of-sight projectors. With CAD drawing, the computer generates the view automatically if a 3D model of the object was originally created.

3. Classifications of Planes and Lines
A line that lies in two principal planes of projection will appear normal (showing its true length) in two views and is named for the planes it lies in, and will appear as a point in the third principal plane.
A line in one principal plane of projection will appear normal (showing its true length) in one view and is named for the plane it lies in, and it is inclined to the other principal planes.
A line in none of the principal planes of projection called an oblique line, will not appear normal in any of the principal views.

4. Classifications of Planes and Lines
LINES IN SPACE

5. Classifications of Planes and Lines
A plane parallel to one of the principal planes of projection receives its name from that principal plane and will appear normal (showing its true length) in that one principal view.
A plane inclined to one principal plane of projection will also be inclined to another principal plane and will not appear normal in any principal view, but will appear as an edge in one view.
A plane inclined to all principal planes of projection called an oblique plane and will not appear normal or as an edge in any of the principal view.

6. Classifications of Planes and Lines
PLANES IN SPACE

7. Classifications of Planes and Lines

8. AUXILIARY VIEWS
FRONT VIEW

9. AUXILIARY VIEWS
TOP VIEW

10. AUXILIARY VIEWS
AUXILIARY VIEW

11. AUXILIARY VIEWS

12. PRIMARY AUXILIARY VIEWS

13. PRIMARY AUXILIARY VIEWS

14. PRIMARY AUXILIARY VIEWS

15. SECONDARY AUXILIARY VIEWS