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# Find the midpoint between two points, the center of a triangle, and other unusual points

Use AutoCAD’s calculator (originally the CAL command and then the QUICKCALC command) to find calculated points, such as the midpoint between two existing points or the center of a triangle. You usually use this command transparently, while drawing a line.

### Use the object snap

There’s a shortcut to start a line (or specify any other point) midway between two points. At the prompt for the point, press and hold Shift and right-click. Then choose Mid Between 2 Points from the shortcut menu of object snaps.

### Use QUICKCALC to draw a line between two endpoints

To start a line midway between two points with QUICKCALC, do the following:

Turn off OSNAP, so you don’t inadvertently snap to an object snap, especially if you’re near other objects.

Start the LINE command.

At the Specify first point: prompt, type ‘quickcalc (or just ‘qc) and press Enter.

In the expression box, type (end+end)/2 as you see here, and then press Enter.

QUICKCALC

At the >> Select entity for END snap: prompt, use the pickbox to pick a point.

At the >> Select entity for END snap: prompt, pick a second point.

Continue drawing the line. The line starts at the midpoint between the two points you specified.

Draw a line between two centers

To use circle centers, type (cen+cen)/2 and follow the same procedure.

### Start a line at the center of a triangle

To start a line at the center of a triangle, you use a similar technique:

Turn off OSNAP, so you don’t inadvertently snap to an object snap, especially if you’re near other objects.

Start the LINE command.

At the Specify first point: prompt, type ‘qc and press Enter.

Type (end+end+end)/3 in the QuickCalc expression box and press Enter.

At the >> Select entity for END snap: prompt, use the pickbox to pick a point.

At the >> Select entity for END snap: prompt, pick a second point.

At the >> Select entity for END snap: prompt, pick a third point.

Continue drawing the line.

The line starts at the center of the triangle, as you see here.

Line Drawing

### Find the intersection of two lines based on their 4 endpoints

Let’s say you want to start a line at the intersection of two lines, without drawing the two lines.

Start the LINE command.

At the prompt, type ‘qc and press Enter.

Type ill(end,end,end,end) in the QuickCalc expression box and press Enter.

At the prompts, select the endpoint of the first imaginary line, then its other endpoint. Then select the endpoints of the second line.

Continuing drawing the line.

Line Drawing

Tip: If you expand the Variables section of the QuickCalc dialog box, you can choose the ille variable to do the same operation.

What methods do you use to find unusual points?

### 10 comments to Find the midpoint between two points, the center of a triangle, and other unusual points

• I use AutoCAD LT 2011. I was not able to duplicate these procedures. quickcalc would not start after starting the line command with either the “qc” or “quickcalc” commands. If I had quick calc running and then started the line command, the interface was not allowed. Are there any suggestions?

• Garry Ynion

i agree with u, i used autocad 2010.

• Ellen

I just tested it and didn’t have any problem. Did you use the apostrophe before qc or quickcalc? That’s what makes the command transparent.

• Garry Ynion

i have just used the ‘cal, and it works now.

• Garry Ynion

and i also tried the ‘qc, and it works also. tnx

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• Nicolas

Hi ,

Thank you for the explanation. I have been looking for that info for a long time. It works with both ‘qc and ‘cal given we use them transparently and it does work in Autocad 2012.

• Kellu

After the LINE command and typping formula in calculator i get “Unable to pick points during command”