Unit 3: Projection of Solids & Floor Plans Overview
Engineering Graphics Unit 3 covers projections of regular solids, solids inclined to HP and VP, auxiliary views, annotation, dimensioning, scales and floor plans.
This unit is important for RGPV exams because projection of prism, pyramid, cylinder, auxiliary views, dimensioning rules and floor plan symbols are repeatedly asked.
Unit 3 Syllabus
- Projections of Regular Solids
- Solids inclined to both HP and VP
- Auxiliary Views
- Simple Annotation
- Dimensioning
- Scale in Drawing
- Floor Plans
- Symbols of Windows, Doors and Fixtures
- Building Fixture Symbols
Most Important Topics for Exam
Projection of Solids
Most important drawing topic involving prism, pyramid, cylinder and cone.
Auxiliary Views
Used to obtain true shape and true size of inclined surfaces.
Floor Plans
Important drawing question with doors, windows and sanitary fixtures.
Dimensioning
Frequently asked theory topic with rules and methods.
Annotation
Important short note topic for labels, notes and drawing symbols.
Building Symbols
Commonly asked symbols include door, window, WC, bath, sink and shower.
Short Notes for Quick Revision
1. Regular Solids
Regular solids are three-dimensional objects having regular shape and equal dimensions. Common regular solids are prism, pyramid, cylinder, cone and sphere.
2. Projection of Regular Solids
Projection of regular solids means drawing front view and top view of solids in simple or inclined positions.
3. Important Terms
Axis is an imaginary line passing through the center of a solid. Base is the bottom surface of a solid. Generators are lines that generate curved surfaces.
4. Solids Inclined to HP and VP
When the axis of a solid is inclined to both Horizontal Plane and Vertical Plane, projections are drawn using change of position method or auxiliary view method.
5. Auxiliary Views
Auxiliary views are additional views used to show true shape and true size of inclined surfaces.
6. Types of Auxiliary Views
The two common types are Auxiliary Front View and Auxiliary Top View.
7. Annotation
Annotation means writing notes, labels and symbols on engineering drawings. It improves understanding and provides additional information.
8. Dimensioning
Dimensioning means indicating sizes and measurements on engineering drawings. It includes dimension line, extension line, arrow heads and dimension figures.
9. Scale
Scale is used to represent actual dimensions in reduced or enlarged form. Representative Fraction is the ratio of drawing length to actual length.
10. Floor Plan
A floor plan is the top view of a building showing arrangement of rooms, walls, doors, windows and fixtures.
11. Building Fixtures
Common fixtures in floor plans are WC, bath, sink and shower.
12. Building Symbols
Common drawing symbols include door symbol, window symbol, ventilator symbol, sink symbol and WC symbol.
Important Terms Table
| Term | Meaning |
|---|---|
| Prism | Regular solid with equal and parallel polygonal bases |
| Pyramid | Solid with polygonal base and triangular faces meeting at apex |
| Cylinder | Solid with circular base and curved surface |
| Axis | Imaginary line passing through center of solid |
| Auxiliary View | Additional view used to obtain true shape or true size |
| Annotation | Notes, labels and symbols written on drawings |
| Dimensioning | Showing size and measurement on drawing |
| Floor Plan | Top view of building showing rooms, walls and fixtures |
Dimensioning Rules
| Rule | Explanation |
|---|---|
| Clear Dimensions | Dimensions should be clear and easy to read |
| No Repetition | Avoid repeating the same dimensions |
| Standard Symbols | Use standard symbols and arrow heads |
| Neat Placement | Dimension lines should be placed neatly outside the drawing where possible |
| Readable Figures | Dimension figures should be readable and properly aligned |
Floor Plan Symbols
| Symbol / Fixture | Use in Floor Plan |
|---|---|
| Door | Shows entrance or opening in wall |
| Window | Shows ventilation and light opening |
| Ventilator | Shows small ventilation opening |
| WC | Water closet or toilet fixture |
| Bath | Bathroom area |
| Sink | Kitchen or wash area fixture |
| Shower | Bathroom shower unit |
Important Questions
- Draw projections of prism inclined to HP and VP.
- Draw projections of pentagonal prism resting on HP and inclined to VP.
- Draw projections of hexagonal prism inclined to both HP and VP.
- Draw projections of square pyramid inclined to HP and VP.
- Draw projections of cylinder inclined to HP and VP.
- Explain auxiliary view method with neat sketches.
- Draw auxiliary views of inclined surfaces.
- Explain annotation and its importance in engineering drawings.
- Explain dimensioning rules and methods.
- Draw a floor plan showing doors, windows and fixtures.
- Explain symbols used in floor plans with neat sketches.
- Explain projection methods for solids inclined to both planes.
PYQ Analysis Table
According to the uploaded Unit 3 PYQ analysis, projection of solids, section of solids, auxiliary view method, floor plans and dimensioning rules are repeatedly asked in RGPV Engineering Graphics exams. :contentReference[oaicite:0]{index=0}
| Topic | Repeated Pattern | Frequency |
|---|---|---|
| Projection of Solids | Projection of prism, pyramid, cylinder and cone inclined to HP/VP | ⭐⭐⭐⭐⭐ |
| Auxiliary Views | Auxiliary view method for inclined surfaces | ⭐⭐⭐⭐ |
| Floor Plans & Symbols | Floor plan with doors, windows, WC and sink | ⭐⭐⭐⭐ |
| Dimensioning | Rules of dimensioning and examples | ⭐⭐⭐⭐ |
| Annotation | Short note and applications | ⭐⭐⭐ |
| Building Symbols | Symbols of doors, windows and fixtures | ⭐⭐⭐ |
High Chance Questions for Next Exam
- Projection of prism inclined to both planes.
- Projection of cylinder inclined to HP and VP.
- Auxiliary view construction.
- Dimensioning rules and methods.
- Floor plan drawing with fixtures.
- Symbols used in engineering building drawings.
- Projection of cylinder and pyramid.
- Annotation and scale problems.
Topic Weightage Analysis
| Topic | Importance |
|---|---|
| Projection of Solids | ⭐⭐⭐⭐⭐ |
| Auxiliary Views | ⭐⭐⭐⭐⭐ |
| Floor Plans | ⭐⭐⭐⭐ |
| Dimensioning | ⭐⭐⭐⭐ |
| Annotation | ⭐⭐⭐ |
| Building Symbols | ⭐⭐⭐ |
Download Engineering Graphics Unit 3 PDFs
Download complete Unit 3 notes, important questions and PYQ analysis for RGPV Engineering Graphics exam preparation.
Download Notes PDFHow to Prepare Graphics Unit 3
- Practice projections of prism, pyramid and cylinder daily.
- Revise auxiliary view method for true shape and true size.
- Learn standard building symbols for doors, windows, WC, sink and bath.
- Practice neat floor plan drawings with dimensions.
- Revise dimensioning rules and annotation methods.
- Use proper construction lines and darken only final visible lines.
Frequently Asked Questions
Is Engineering Graphics Unit 3 important for RGPV exams?
Yes, Unit 3 is important because projection of solids, auxiliary views, floor plans and dimensioning are repeatedly asked.
Which topic is most important in Graphics Unit 3?
Projection of Solids and Auxiliary Views are the most important topics.
Are floor plan questions asked from Unit 3?
Yes, floor plans with doors, windows and fixtures are commonly asked.
How should I prepare Unit 3 quickly?
Focus on projection of prism, pyramid, cylinder, auxiliary views, dimensioning rules and building symbols.
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