72
AutoCAD and Its Applications—Basics
Figure 2-21 describes angular unit formats. After selecting the linear and angular
units and precision, pick the
OK
button to exit the
Drawing Units
dialog box.
Exercise 2-6
Complete the exercise on the companion website.
www.g-wlearning.com/CAD
Figure 2-20.
The
Direction
Control
dialog box.
Set
direction
of 0°
Specify
another
angle
Figure 2-21.
Angular unit formats available in the
Drawing Units
dialog box. Select the appropriate type
and precision for the specific drawing application.
Type Applications and Characteristics Example
Decimal
Degrees
• Mechanical, architectural, and structural drafting applications.
• Degrees and decimal parts of a degree.
• Initial default setting.
45°
Deg/Min/Sec • Civil and sometimes mechanical, architectural, and structural
drafting applications.
• • Degrees De gr ee s, m m inutes, in ut es and an d seconds se co nd s.
• 1 degree = 60 minutes; 1 minute = 60 seconds.
45°0’0”
Grads • Grad is the abbreviation for gradient.
• One-quarter of a circle has 100 grads; a full circle has 400 grads.
50.000g
Radians • A radian is an angular unit of measurement in which
2π 2 π radians ad a s = 360° 3 60 and a d π π radians ad a s = 180°. 80 Pi (π) ( π ) is s approximatelya a pp o te ly
equal to 3.1416.
• A 90° angle has π/2 radians and an arc length of π/2.
• Chan Ch ing gi th he pre i ci ion si d d i is lays pl he th radian di v lue al rou d nd d ed to
the specified decimal place.
0.785r
Surveyor • Civil drafting applications.
• Degrees, minutes, and seconds.
• Uses bearings. A bearing is the direction of a line with
respect to one of the quadrants of a compass. Bearings are
measur me as ur d ed ed c c l lo lo k ck ck ise wi wi se o o r r countercl co un te rc lo lo k ck ck ise wi wi se (d ( ( de de pe pe di nd nd in in g g on on t t h he he
quadrant), beginning from either north or south.
• An angle measuring 55°45’22” from north toward west is
expressed as N55°45’22”W.
• Set precision to degrees, degrees/minutes, degrees/minutes/
seconds, or decimal display accuracy of the seconds part of
the measurement.
N45°E