This document contains engineering graphics lecture notes on the projection of planes. It discusses different types of plane figures and planes, including perpendicular, oblique, and inclined planes. It provides examples and step-by-step instructions for projecting planes that are perpendicular, parallel, or inclined to the horizontal and vertical planes. The document aims to teach students how to draw the projections of various plane figures based on their orientation relative to the reference planes.

1. ENGINEERING GRAPHICS
By
R.Nathan
Assistant Professor
Department of Mechanical Engineering
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012

2. UNIT – 2
“PROJECTION OF PLANES”
Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012

3. Engineering Graphics Lecture Notes
TYPES OF PLANE FIGURES
SQUARE RECTANGLE TRIANGLE
CIRCLE TRAPEZOID PARALLELOGRAM
PENTAGON HEXAGON DIAMOND

4. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
TYPES OF PLANES
PERPENDICULAR PLANES
Planes which are perpendicular to one of the principal planes of
projection and inclined or parallel to the other
OBLIQUE PLANES
Planes inclined to both the reference planes
TRACE OF PLANE
HORIZONTAL TRACE
The intecsection line of the plane surface with H.P
VERTICAL TRACE
The intecsection line of the plane surface with V.P

5. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
PROJECTION OF PLANE PERPENDICULAR TO V.P AND PARALLEL TO
H.P

6. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
EXAMPLE:-
An equilateral triangle ABC of 50 mm side has its plane parallel to H.P
and side AB parallel to V.P Draw its projections when the corner C is 15
mm from H.P and 45 mm from the V.P

7. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
PROJECTION OF PLANE PERPENDICULAR TO H.P AND PARALLEL TO
V.P

8. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
EXAMPLE:-
An equilateral triangle ABC of 50 mm side is parallel to and 15 mm in
front of V.P, its base AB is parallel to and 75 mm above H.P, Draw the
projections of the triangle when the corner is near the H.P

9. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
PROJECTION OF PLANE PERPENDICULAR TO BOTH H.P AND V.P

10. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
EXAMPLE:-
A semicircle of diameter, CD = 50 is kept in the 1st
quadrant such that
its diameter is perpendicular to V.P and H.P, Draw its projections,
when the diameter is near V.P, distance of diameter from H.P is 15
mm and from V.P is 20

11. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
PROJECTION OF PLANE PERPENDICULAR TO V.P AND INCLINED TO H.P

12. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
EXAMPLE:-
A thin horizontal plate of 15 mm sides is inclined at 45° to the H.P and
perpendicular to V.P, two of its parallel edges is parallel to V.P, the
plate is 10 mm above H.P and 15 mm infront of V.P

13. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
PROJECTION OF PLANE PERPENDICULAR TO H.P AND INCLINED TO V.P

14. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
EXAMPLE:-
Draw the projections of a circular lamina of 30 mm diameter. The
lamina is inclined a an angle of 45° to V.P

15. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
PROJECTION OF OBLIQUE PLANES
When the plane is inclined to both the reference planes, its
projections are drawn in three stages
First stage, the plane is assumed to be parallel to H.P
Second stage, it is tilted so as to make the required angle with the
H.P, its Front View in this position will be a line while its Top View
will be smaller is size
Third stage, the plane is turned to the required inclination with the
V.P, only the position of the Top View will alter.
Its shape and size will not be affected

16. Engineering Graphics Lecture Notes
C.R.ENGINEERING COLLEGE
Alagarkovil, Madurai - 625301
I - SEMESTER 04.10.2012
EXAMPLE:-
Draw the projections of a regular hexagon of 20 mm side, having one
of its sides in the H.P and inclined at 45° to the V.P; and its surface
making an angle of 30° with the H.P