This document discusses the projection of lines in engineering graphics. It explains that lines can be parallel, perpendicular, or inclined to the horizontal and vertical planes. The key rules are: 1) A line parallel to both planes will have equal length projections. 2) A line perpendicular to one plane will be a point in the view parallel to that plane. 3) A line contained in a plane will show its true length in that view. Examples are given showing how to project lines in different positions in relation to the planes.

1. ACTIVE LEARNING ASSIGNMENT
ENGINEERING GRAPHICS(2110013)
PROJECTION OF LINE
PREPARED BY: GUIDED BY:
Chovatiya jay (150120116011) Prof. Someshvar Pandey
Chitte Rohan (150120116012)
Bhad Tushar (150120116005)
BRANCH: INFORMATION TECHNOLOGY- D-D1
SEMESTER:2 (EVEN)

2. In orthographic projections space is
divided into four quadrants
By two reference planes : H.P. And V.P.
Point may be situated in any one of these
quadrants
It may also be on any one of the reference
planes

3. 3PES

4. Point situated above HP and in front of VP is in
1Q
Point situated above HP and behind VP is in 2Q.
Point situated below hp and behind vp is in 3q.
Point situated below hp and in front of vp is in
4q.

5. The line in space may be parallel,
perpendicular or inclined to either the HP
or the VP or both of them
It may be in one or both the reference
planes
The line ends may be in one or two
quadrants.
5PES

6. Case i: straight line parallel to both
planes
Rule no. I a straight line represents its true
length in that plane to which it is parallel
In fig. Line ab parallel to HP and VP
Distances of end points from HP and VP
are equal
Top view ab and front view a’b’ are equal to
line ab and parallel to xy line

8. Case ii:perpendicular to one plane
and parallel to other
Rule ii: line represents point in that
plane to which it is perpendicular
When a line perpendicular to one
plane it will be parallel to other
reference plane,as hp and vp are
perpendicular to each other

9. Line perpendicular to hp and parallel
to vp
In fig. Line ab is perpendicular to hp, and
parallel to vp
Its front view a’b’ will be equal to true
length of line ab
Top view ab will be a point as shown in hp

11. Case iii: line contained by one or both
the planes
Rule iii: line represents its true length in
that plane to which the line is contained
Projectors of true length always come on xy
line

12. SUMMARY OF PROJECTION OF LINES
S.N
O
POSITION OF LINE FRONT VIEW TOP VIEW
1 LINE PARALLEL TO BOTH V.P
& H.P
HORIZONTAL
LINE PARALLEL
TO XY
HORIZONTAL
LINE PARALLEL
TO XY
2 LINE PERPENDICULAR TO
H.P AND PARALLEL TO V.P
VERTICAL LINE POINT
3 LINE PERPENDICULAR TO V.P
AND PARALLEL TO H.P
POINT VERTICAL LINE
4 LINE PARALLEL TO H.P AND
INCLINED TO V.P AT ANGLE
“Ѳ”
LINE PARALLEL
TO XY WITH
FORESHORTENE
D LENGTH
INCLINED LINE
WITH TRUE
LENGTH
5 LINE PARALLEL TO V.P AND
INCLINED TO H.P AT
ANGLE“Ѳ”
INCLINED LINE
WITH TRUE
LENGTH
LINE PARALLEL
TO XY WITH
FORESHORTENE
D LENGTH

13. EXAMPLE PROBLEMS:-
I.DRAW THE PROJECTION OF A LINE PQ, 25 MM LONG IN THE
FOLLOWING POSITIONS
1.Perpendicular to the H.P., 20 mm infront of V.P and its one end 15
mm above the H.P

14. EXAMPLE PROBLEMS:-
II.DRAW THE PROJECTION OF A LINE PQ, 25 MM LONG IN THE
FOLLOWING POSITIONS
1.Perpendicular to the V.P., 25 mm above the H.P and its end in the
V.P

15. EXAMPLE PROBLEMS:-
IV.Draw the projection of a 30 mm long AB, straight line parallel to and
30 mm above H.P and in the V.P