(Preparation - download the first diagram below, print and make a copy for
all students) Hand them out and ask:
a) Which is the longest edge in Fig 1 and why? (AD because it is closest - CA and AB recede)
b) What are the circumstances that would make CA=CB? (if the block was centrally positioned between the LVP and RVP)
c) Why is CA bigger than AB in Fig 2?
d) Measure all lines in Fig 2. Are any two the some size? (Discuss what we mean by real size or apparent size?)
e) Fig 3 does not look quite as 'square' as it should, why is that? (AB and CA are slightly to long making the block appear squatter than the others)
We must learn to use our eyes and judge distances and proportions.
We must keep drawing them until they look right. It is the same if
drawing a face or a box for always we must judge one thing in relation
to all the others in the same space.
The simplest object to practice and draw is the cube and we can use the cube to make many other shapes. If the cube is nearer the RVP AC will always be larger than AB while the reverse applies for the LVP.
Construct margin and title box then:
b) Draw a cube in the approximate size and position as shown above.
c) Extend the line 'ab' to four times its length.
d) Draw the diagonal ... extend it, and form the square.
e) Construct diagonal and the 16 little boxes as shown
f) Mark approximately 3/4 lengths along the diagonals
g) Lightly draw in your circle.
h) Firm it in.
i) Give the disc thickness as shown. The lines to the RVP form 'tangents' to the circle. Sketch in lightly until it looks right then firm it in. The teacher should check ...
j) In the inner four squares draw another circle.
k) Firm it in and complete as shown above.
Shade the drawing and add another letter.
There are thousands of variations of this drawing. The student could perhaps try and draw their own initials in the other direction, or using just the CVP on the ground. The more confident can try and draw a large 'S' for instance as homework or a special project.