Chapter 6 Basic Geometric Constructions 211
23. What CAD command is used to enlarge or
reduce objects in size?
24. A(n) _____ is any part of a circle or other
curved line.
25. What CAD command is used to draw circles?
26. A(n) _____ is a line or curve that touches the
surface of a circle or an arc at only one point.
27. What CAD command is used to trim away
unwanted portions of a construction?
28. Laying off the circumference of a circle is
also referred to as locating the true length
or _____ length.
29. The circumference of a circle may be cal-
culated very accurately by multiplying the
diameter by _____.
30. Name four items of data identified for a fi
circle when using the
List
command.
31. The _____ length is the length of a line that
connects the endpoints of an arc.
Problems and Activities
The following problems have been designed
to give you experience in performing simple
geometricconstructionsusedindrafting.Practical
applications of geometry applied to drafting are
included to acquaint you with typical problems
the drafter, designer, or engineer must solve.
If you are drawing problems manually, use the
Layout I sheet format given in the Reference Section.
Place the drawing paper horizontally on the draw-
ing board or table. Use the title block shown in
Layout I and lay out the problems carefully, making
the best use of space available. A freehand sketch of
the problem and solution will help.
If you are using a CAD system, create layers
and set up drawing aids as needed. Use the most
useful commands and tools available to you.
Save each problem as a drawing file and save fi
your work frequently.
Accuracy is extremely important in drawing
geometric constructions. On manual drawings,
use a hard lead (2H to 4H) sharpened to a fine fi
conical point and draw light lines. When the
construction is complete, darken the required
lines and leave all construction lines as drawn to
show your work.
Problems that call for “any convenient length”
or “any convenient angle” should not be measured
with the scale or laid out with the T-square and
triangles. Do not dimension the problems.
Complete the problems as assigned by your
instructor. A suggested layout for the first four fi
problems is shown in Figure 6-62.
Figure 6-62. Use the Layout I sheet format from the Reference Section as a guide when drawing your border and title block
for the problems in the Problems and Activities section. For Problems 1–4, divide your drawing sheet as shown here.
1 2
3
A
B
4