Points, Lines, and Planes
Points, Lines, and Planes
Basic Geometric Elements
Points, Lines, and Planes Individually Represented
Basic Geometric Elements
Normal Edges
A normal edge is a line that is
perpendicular to a plane of projection.
It appears as a point on the plane of
projection to which it is perpendicular
and as a true length line on adjacent
planes.
Basic Geometric Elements
Inclined Edges
An inclined edge is a line that is
parallel to a plane of projection but
inclined to adjacent planes.
An inclined edge appears true length
on the plane to which it is parallel and
foreshortened on adjacent planes.
Basic Geometric Elements
Oblique Edges
An oblique edge is a plane that is
oblique to all planes of projection.
Since it is not perpendicular to any
plane it cannot appear as a point in any
view.
Since it is not parallel to any plane it
cannot appear true length in any view.
An oblique edge appears foreshortened
and in an inclined position in every
view.
Basic Geometric Elements
Views of Points and Lines
Intersecting Lines
Nonintersecting Lines
Visibility of Nonintersecting Lines
Geometric Constructions
Solids
Solids bounded by
plane surfaces are
called polyhedra.
The surfaces are
called faces.
If the faces are equal
regular polygons the
solids are called
regular polyhedra.
Visibility of Nonintersecting lines
Visibility of Nonintersecting lines of a Tetrahedron
True Length of an Oblique Line
True Length of an Oblique Line
True Length by
Revolution
Point View of a Line
Straight Line in a Plane
Point in a Plane
Edge View of a Plane
Piercing Point
Piercing Point – Edge View Method
Piercing Point
Piercing Point – Cutting Plane Method
Piercing Point
Piercing Point – Cutting
Plane Method