AutoCADs Geometeric Calculator

On-line Geometric Calculator

          Cal is one of the most overlooked command and the most useful. There is almost 18 pages dedicated to it in the R13 manual but, I believe it has been around since R12. Cal can be used instream (while you are executing a command). Cal can be used on the command line to add, subtract, multiply, divide and all your basic mathematics.
command: cal<return>
Initializing...>> Expression: 2+2<return>
4
           Here is an example of how it would work instream. I want a circle that has a radius of 230.23 + 210.23 and I don't want to pull out my calculator and add it up first so I do:
command: CIRCLE 3P/2P/TTR/<Center point>: pick point Diameter/<Radius>: 'cal<return>
Initializing...>> Expression: 230.23 + 210.23<return>
and whala cal just fed the circle command the sum of 230.23 and 210.23 which equals a radius of 440.46. Cal also works with complex problems too like (2 + 4)/5*6 would add 2 and 4 and then divide that total by 5 and then multiply that times 6. After I learned cal I got rid of my calculator (actual I spilt coffee on it and it died but that is another story. point is I never replaced it).
           Of course if that was all it could do I would not be excited either but, there is more, oh yeah much more it can do. They call it a geometric calculator in the manual because it does geometry too (DUH). If you really want to get in-depth with Cal I suggest you RTFM (read the manual). Here are some of my favorite quick little cals

command

it does this for you

MEE

returns the midpoint between two end points (end snaps are already selected for you)

(cur+cur)/2

finds the midpoint between any two points (you must supply the snaps)

ANG(NEA, NEA)

get an angle from from 2 points (nearest snap is selected here)

ANG(INT,NEA,NEA)

here it figures an internal angle. You must first give it the apex point of the angle and then a point on the angle lines.

RAD

returns the radius of an existing arc or circle