Descriptive Geometry

# Descriptive Geometry

## Descriptive Geometry

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##### Presentation Transcript

1. Descriptive Geometry Ref. Descriptive Geometry Metric PARE/LOVING/HILL Fifth edition

2. Descriptive Geometry • Descriptive Geometry: is the science of graphic representation and solution and space problems

3. projections • Tow common types of projections: 1) perspective projections (used by architects or artists) 2) orthographic projections (perpendicular to the object)

4. Principal Views

5. Draw the profile

6. Steps to obtain a view • Establish the line of sight. • Introduce the folding line • Transfer distances to the new view • Determine visibility and complete the view

7. Step 1: Establish the line of sight. Primary Auxiliary Views Step 2: Introduce the folding line Step 3: transfer distances a,e d,h y b,f c,g H 1 Step 4: determine visibility and complete view D2 1 D1 D y h d g k1 e D2 c y f a D1 f,e g,h b b,a c,d

8. Primary Auxiliary Views

9. View 1 is an auxiliary view projected from the front View

10. Edge View of a plane

11. Chapter 3: LINES

12. Frontal Line

13. Frontal Line

14. the true angel between a line and any projection plane appears in any view shows the line in true length and the projection plane in Edge View.

15. Level (Horizontal) Line

16. Level Line

17. Profile Line

18. Profile Line

19. True Length of an Oblique Line

20. True Length of an Oblique Line

21. Bearing , Slope, and Grade N N aH aH S55oE 55 b b Bearing: a term used to describe the direction of a line on the earth’s surface

22. Azimuth Bearing N aH aH 125o N125o b b

23. problem • A 160-m segment AB of a power line has a bearing of N 60o and a downward slope of 20o from the given point A. Complete the front and top views. ah aF

24. D1 D1 D1 D1 b 1 20o H 160 m N b N 60o a1 ah H F aF b

25. Grade Grade: another way to describe the inclination of a line from the horizontal Plane