Chapter 6 Basic Geometric Constructions 179
3. Enter the
Edge
option and select an
endpoint. Then, enter the given side
length. If you move the cursor, the square
is drawn dynamically in a counterclock-
wise direction. You can enter coordinates
to specify the length and direction of the
edge, or you can use Ortho mode and
direct distance entry.
4. When you specify the endpoint of the
fi rst edge, the square is generated auto- fi
matically. This is the required square.
Figure 6-26. Constructing a square. A—If a side
length is known, a square can be constructed using a
straightedge and triangle. B—A compass can also be
used for this construction.
A B
D C
A
E
E1 E2
J
F
H G
B
BC. Measure this line to the correct
length.
4. Draw Line AD. This line should be at
right angles to both Line AB and Line
CD. This line completes the required
square.
Using a Compass
(Manual Procedure)
1. Given the length of one side, use a com-
pass to lay off Line EF as the base line,
Figure 6-26B.
2. Construct a perpendicular to Line EF at
Point E by extending Line EF to the left
and striking equal arcs on the base line
from Point E. (The arcs can be any con-
venient length.) These points are Point E
1
and Point E
2
.
3. From these two points, strike equal arcs
to intersect at Point J.
4. Draw a line from Point E through Point J.
Set the compass for the distance between
Point E and Point F. Mark off this dis-
tance on the line running through Point J.
This point becomes Point H.
5. From Points F and H, using the same
compass setting, lay off intersecting arcs
(Arcs FG and HG).
6. Lines drawn to this intersection complete
the required square.
Using the Polygon Command
(CAD Procedure)
1. Side length AB is given. Refer to
Figure 6-26A.
2. Enter the
Polygon
command and specify
the number of sides as four.