2004

260 | Chapter 15 Use Precision Tools
Calculating Points
To calculate a point
You can use
CAL whenever you need to calculate a point or a number within
an AutoCAD command.
For example, you enter (mid+cen)/2 to specify a point halfway between the
midpoint of a line and the center of a circle.
The following example uses
CAL as a construction tool. It locates a center
point for a new circle, and then calculates one fifth of the radius of an
existing circle.
Here is the command line sequence:
Command: circle
Specify center point for circle or [3P/2P/Ttr (tan tan radius)]: 'cal
>> Expression: (mid+cen)/2
>> Select entity for MID snap: Select the notch line (1)
>> Select entity for CEN snap: Select the large circle (2)
Diameter/<Radius>: 'cal
>> Expression: 1/5*rad
>> Select circle, arc or polyline segment for RAD function: Select the large
circle (3)
2 and 3
center of circle
(mid+cen)/2
1