1. Engineering Graphics Anna Edusat course on “Engineering Graphics ” Lecture – 4 Projections of Lines Dr. Vela Murali,Ph.D., Head and Professor i/c - Engineering Design Div., Department of Mechanical Engineering, College of Engineering, Guindy, Anna University, Chennai – 600 025 1 By

2. 2 ORTHOGRAPHIC PROJECTIONS OF STRAIGHT LINES 1. Draw the projections of the following straight lines of length 70 mm on to same VP and HP

3. 3 (i) Line AB, 30 mm above HP, 20 mm in front of VP and parallel to both the planes

4. 4 (ii) Line CD, 30 mm above HP, in VP and parallel to both the planes

5. 5 (iii) Line EF, 30 mm in front of VP, in HP and parallel to both the planes

6. 6 (iv) Line AB, 30 mm below HP, 20 mm behind VP and parallel to both the planes

7. 7 (v) Line CD, 30 mm below HP, in VP and parallel to both the planes

8. 8 (vi) Line EF, 30 mm in front of VP, in HP and parallel to both the planes

9. 9 2. Draw the projections of the following straight lines of length 60 mm on to same VP and HP

10. 10 (i) Line AB, 25 mm in front of VP and point ‘A’ is 20 mm above HP and the line is parallel to VP and perpendicular to HP.

11. 11 (ii) Line AB, in VP and point ‘A’ is 20 mm above HP and the line is parallel to VP and perpendicular to HP.

12. 12 (iii) Line CD, 25 mm above HP and point ‘C’ is 20 mm in front of VP and the line is parallel to HP and perpendicular to VP.

13. 13 (iv) Line CD, in HP and point ‘C’ is 20 mm in front of VP and the line is parallel to HP and perpendicular to VP.

14. 14 (4) Draw the three principal views of a line 80 mm long when it is placed parallel to both HP and VP. One of the ends of the line is 70 mm above HP, 60 mm in front of VP and 30 mm in front of right PP.

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16. 16 (5) Draw the projections of a line 80 mm long placed parallel to VP, perpendicular to HP. The line is 70 mm in front of VP and 60 mm in front of right PP. The lower end of the line is 30 mm above HP

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18. 18 (6) A line AB 80 mm long is inclined at 30 o to HP and parallel to VP. The line is 90 mm in front of VP. The lower end A is 35 mm above HP, 110 mm in front of the right PP and is away from it than the lower end. Draw its projections.

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20. 20 Line inclined to both the HP and VP

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22. 22 (7) A line AB 60 mm long has one of its extremities 20 mm in front of VP and 15 mm above HP. The line is inclined at 25 o to HP and 40 o to VP. Draw its top and front views.

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24. 24 (8) A line AB 70 mm has its end A 15 mm in front of VP and 20 mm above HP and the other end B is 60 mm in front of VP and 50 mm above HP. Draw projections of the line and find the inclinations of the line with HP and VP.

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26. 26 (9) A line PQ has its end P 15 mm above HP and 10 mm in front of VP. The end Q is 55 mm above HP, and line is inclined at 30 o to HP. The distance between the end projectors of the line when measured parallel to the line of intersection of HP and VP is 50 mm. Draw projections of the line and find the inclination of the line with VP.

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28. 28 (10) The front view of a line 90 mm long is inclined at 45 o to the XY line, a ’ b’ being 65 mm long. a ’ is 15 mm above the XY line. The point A is in VP. Draw the projections of the line and find its inclinations with HP and VP.

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30. 30 (11) The side view of a line AB 80 mm long makes an angle of 30 o to the XY line. Draw the top and front views of the line when the length of the profile view is 50 mm. Take the point A to be 15 mm above and 60 mm in front of VP, the point B being closest to VP.

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32. 32 (12) Draw the projections of the line AB, 100 mm long, inclined at 45 o to HP and 30 o to VP, the end A is in HP and the end B is in VP. Find the shortest distance between the line AB and the line of intersection of planes of projection.

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34. 34 To find the true length and true inclination of a line – Rotating line method

35. 35 Rotating Trapezoidal method

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37. 37 (13) The front view of the line AB of length 70 mm is inclined at 30 o to xy line and measures 45 mm. The end A is 20 mm above HP and 25 mm in front of VP. Draw the projections of the line and find the inclinations with HP and VP by i) rotating line method and ii) trapezoidal method.

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