complex drawings.pptxhow to draw complex objects with instruments

how to draw complex objects with instruments

1. Drawing complex objects Gr.9

2. Swbat Implement different instruments to create more complex objects

3. Do now List 4 line types

4. Do now answer Dark lines Feint lines Dashed line Wavy lines

5. Drawing complex objects The 3-dimensional objects you will need to draw in your technology are unlikely to be as simple as those you used in the previous activities. Objects you design and need to draw may not be regular or even shaped, they may have cut-outs and curves, or they may be asymmetrical.

6. To draw these objects accurately you may need to use additional instruments. Some equipment you could use are a T square, set squares and a protractor.

7. Using a T square A T square is shaped like a T. It has a metal ruler attached at right angles to a solid piece of metal or plastic. To use a T square your piece of paper must be attached to a drawing board with straight edges. The short edge of the T square fits over the top or side of the board and the ruler part will be across your page. You can then use the ruler to draw straight lines and parallel lines.

8. Using set squares There are two types of set squares. They are named according to the angle of their corners. There is a 450 set square and a 30/60 set square. Set squares are often used with T squares. By putting a set square onto the ruler of a T square, you can draw parallel lines perpendicular to the line drawn by the T square. You can also use the set square to draw diagonal lines.

9. Set squires: Common errors Common errors when using T-squares and set squares are that gaps are allowed to develop between the T-square and the edge of the board or the set square and the T-square. This leads to inaccurate drawing with angles being incorrect. Adjustable set squares allow a range of angles to be drawn accurately. They can be adjusted to a variety of angles which means only one set square is required. It must still be used by resting accurately on a T-square.

10. advantages of a set square Here is list of things you can do with set square: Draw perpendicular line. draw perpendicular edges. Draw some standard measured angles( The two set squares are named according to their angles.)

11. Activity 1. Explain the term set square 2. Name two types of set squares 3. Briefly explain how to use a set square 4. list three advantages of using set squares 5. Explain a common error made when using a set square

12. Do now List two instruments to draw complex objects

13. answer T square Protractor

14. Using a protractor You can use a protractor to measure existing angles, and to draw angles. Protractors have angles written on the curved side and a line with a centre point on the straight side. To draw an angle you put the cross in the middle of the straight line at the point at which the angle will begin. Then mark with a dot the angle you want. Remove the protractor and draw a line from the dot to the point where the angle should start. To use a protractor to measure an existing angle, put the cross over the point where the angle begins and then read where it crosses the markings on the curved line.

15. Activity 1. List three instruments you may use to create accurate drawings 2. Briefly explain why you may need to use instruments to create accurate drawings 3. Explain the term “T square” 4. Explain how to use a T square 5. Explain the term “protractor”