ACTIVE LEARNING ASSIGNMENT ENGINEERING GRAPHICS(2110013)

PROJECTION OF LINE PREPARED BY: GUIDED BY:

Chovatiya jay (150120116011) Prof. Someshvar PandeyChitte Rohan (150120116012)Bhad Tushar (150120116005)

BRANCH: INFORMATION TECHNOLOGY- D-D1SEMESTER:2 (EVEN)

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

3PES

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.

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

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 VPDistances of end points from HP and VP

are equalTop view ab and front view a’b’ are

equal to line ab and parallel to xy line

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

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

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

SUMMARY OF PROJECTION OF LINES

S.NO

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 FORESHORTENED 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 FORESHORTENED LENGTH

EXAMPLE PROBLEMS:-I.DRAW THE PROJECTION OF A LINE PQ, 25 MM LONG IN THE FOLLOWING POSITIONS1.Perpendicular to the H.P., 20 mm infront of V.P and its one end 15 mm above the H.P

EXAMPLE PROBLEMS:-II.DRAW THE PROJECTION OF A LINE PQ, 25 MM LONG IN THE FOLLOWING POSITIONS1.Perpendicular to the V.P., 25 mm above the H.P and its end in the V.P

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