Chapter 6 Basic Geometric Constructions 171
allows you to create a copy of the angle
without changing the original angle.
1. Angle BAC is given and is to be trans-
ferred to a new position at Line A′B′ A A ,
Figure 6-14A.
2. Enter the
Rotate
command and select the
lines making up Angle BAC. Specify the
vertex as the base point of rotation.
3. Enter the
Copy
option when prompted
for a rotation angle.
4. Enter the
Reference
option. Pick the
endpoints of one of the lines making up
Angle BAC, Figure 6-14B.
5. Enter the
Points
option. Pick the endpoints
of Line A′B′ A A . This establishes the desired ′
angle of rotation in relation to Line A′B′ A A
and draws the new angle, Figure 6-14C.
The new angle is rotated about the base
point (the vertex of Angle BAC).
6. Use the
Move
command to relocate the
angle if needed, Figure 6-14D. Select the
vertex as the base point and specify the
endpoint of Line A′B′ A A as the second point.
Erase one of the duplicate lines.
Figure 6-13. Using a compass to transfer an angle.
A
A' B'
A' B'
D'
B
E
F
C
D
A
B
C
A
B
A' B' E'
F' C'
B
E
F
C
A
C
Figure 6-14. Using the Rotate command to transfer an angle. A—The angle is to be copied and rotated to the
location of Line A′B′. A A B—The Copy and Reference options of the Rotate command are used to create the copy.
Points are selected to specify the new orientation of the angle. C—The angle is copied and rotated. D—The
angle is moved to the new location in a separate operation.
A'
A
C
B
A'
B'
B'
A
C
A'
B'
B'
C'
A
B
C
A
B
C
A'
B'
C D
A B
Existing angle
selected with the
Rotate command
Points selected
with the
Reference
option
Points selected
with the
Points option
Angle is copied
and rotated
to orientation
of Line A'B'
B