Lecture 2

Question 1

What are some qualities of 3rd angle projection

Answer 1

• Views are parallel to each other
• Views are perpendicular to each other
• The top is drawn from above
• Left view is drawn from left
• Right view is drawn from right
• Rear view is extreme right or left
• Views can be drawn elsewhere provided it is noted

Question 2

How does a parallel projection plane appear?

Answer 2

Rectangular plane in one plane but as an edge in adjacent plane

Question 3

How does an inclined plane appear?

Answer 3

True length (TL) in one plane and foreshortened in adjacent planes

Question 4

How does a curved plane appear?

Answer 4

True profile in one plane and as edge(line) in adjecent plane

Question 5

How does an oblique surface appear?

Answer 5

As an incline in all three planes

Question 6

What are the three types of pictorial drawings?

Answer 6

1. Axonometric (isometric)
2. Oblique
3. Perspective

Question 7

What does a isometric drawing allow you to see?

Answer 7

A three-dimensional without the distortions created by perspective

Question 8

In isometric drawings do parallel lines converge?

Answer 8

Parallel lines in actuality do not converge, and represent the object’s real proportions and spatial relationships.

Question 9

What are isometric drawings most useful for?

Answer 9

Technical drawings

Question 10

Isometric projection is a from of?

Answer 10

Graphically projection, more specifically axonometric projection

Question 11

What is the angle of isometric drawings for the x, y and z axis?

Answer 11

120 degrees

Question 12

How can isometric projection be visualized?

Answer 12

Considering the view of a cubical room from an upper corner looking towards the opposite lower corner.

Question 13

What does the term isometric mean?

Answer 13

It comes from the Greek for equal measure. Which reflects that the scale along each axis of the projection is the same.

Question 14

What is a problem with isometric projection?

Answer 14

Because the lines representing each dimension are parallel on the page, objects do not appear larger or smaller as they extend closer to the viewer

Question 15

All lines parallel to isometric axis is what?

Answer 15

Isometric lines

Question 16

What are isometric lines foreshortened to?

Answer 16

81/100

Question 17

Are non-isometric lines foreshortened?

Answer 17

They may or may not be foreshortened

Question 18

Are projections of parallel lines parallel?

Answer 18

Yes

Question 19

True or False

All measurements can only be marked on isometric lines?

Answer 19

True

Question 20

What is a oblique projection?

Answer 20

A simple type of graphical projection used for producing pictorial, two-dimensional image of three-dimensional objects

Question 21

What type of projection is oblique projection

Answer 21

Parallel

Question 22

What does oblique projection and orthographic projection have in common?

Answer 22

They are both parallel projection. Parallel lines of the source object produce parallel lines in the projected image.

Question 23

Why are oblique pictorial drawings unsuitable for working drawings?

Answer 23

The angles displayed among the axes, as well as foreshortening factors (scale) are arbitrary. The resulting distortions make the technique unsuitable for working drawings

Question 24

How do you create a true shape image for a oblique pictorial?

Answer 24

Aligning one plane of image parallel to the plane of projection

Question 25

What angle is cabinet projection drawn at?

Answer 25

45 degrees

Question 26

Cavalier drawings receding axis is drawn at what?

Answer 26

30 degrees and 60 degrees

Question 27

What is the role of projection drawing for engineers?

Answer 27

To communicate to others how objects appear

Question 28

What four terms are useful in describing perspective drawings?

Answer 28

1. Picture plan- the surface of the pictorial
2. Horizon line- divides the sky and the land or the sea if outdoors, It is at eye level and changes with elevation
3. Viewing point and direction of view- the location of the eyes relative to the object
4. Vanishing point- the point in which parallel lines converge as they recede into the distance

Question 29

In perspective drawing an object can be represented using how many point perspectives?

Answer 29

One, two or three point perspectives

Question 30

When is one point perspective useful?

Answer 30

When an object is viewed straight on so that its front view lies in the picture plane