182 Section 2 Drafting Techniques and Skills
Figure 6-30. Constructing an inscribed regular pentagon using a compass.
F H G
D
A
F J
E C
H G
D
B
F J
E
A B
C
H G
D
C
Construct an
Inscribed
Regular Pentagon with the
Radius of the Circle Given
CAD
Using a Compass
(Manual Procedure)
1. Radius FG is given, Figure 6-30A.
2. Draw a circle with the given radius and a
center at Point F.
3. Bisect the radius (centerline) of the circle.
The point of bisection is Point H.
4. With Point H as the center, scribe an
arc with a radius equal to HD. This arc
intersects the diameter (centerline) of the
circle at Point J, Figure 6-30B.
5. With the same radius and Point D as
the center, scribe Arc DJ. This arc will
intersect with the circle at Point E.
6. From the same center at Point D, scribe
an equal arc to intersect with the circle at
Point C.
7. With the same radius and with Points E
and C as centers, scribe Arcs EA and
CB. Draw lines between the points of
intersection to form the required regular
pentagon, Figure 6-30C.
Using the Polygon Command
(CAD Procedure)
1. Radius FG is given. Refer to
Figure 6-30A.
2. Enter the
Polygon
command and specify
the number of sides as fi ve. fi
3. Specify Point F as the center of the
pentagon.
4. Enter the
Inscribed
option.
5. Specify the given radius. If you move
the cursor, the pentagon is drawn
dynamically. Enter coordinates to specify
the radius and direction, or use direct
distance entry.
6. The pentagon is generated automatically.
Refer to Figure 6-30C.