## Tip - Draw a circle tangent to 3 equal sized circles

Tips and tricks you want to share with other users. Tutorials, user submitted documentation, etc.

Moderator: andrew

Clive
Premier Member
Posts: 1329
Joined: Thu Aug 25, 2011 9:28 pm
Location: UK

### Tip - Draw a circle tangent to 3 equal sized circles

To draw a circle tangent to 3 equal sized circles (this ones for you Husky )

1. Draw 3 circles (same radius) with centers at any given coordinate points.
2. Set up ' layer ' construction and draw polyline (A) to connect all the centers.
3. Draw a line (B) > using Relative Angle ( LR) set to 90 and at an arbitrary length (say e.g. 100) and 'snap' to the center/middle of one line to produce a line perpendicular to it (90 degree right angle).
4. Repeat for the other line (C), the intersection of these two lines provides the center point (D) for the 4th circle.
5. From any circle draw a line (E) from its center to the intersection, this will be the radius for the 4th circle.
Job done.
Attachments
Circle tangent to 3 equal sized circles..png (15.99 KiB) Viewed 14711 times
Circle tangent to 3 equal sized circles 2..png (35.94 KiB) Viewed 14711 times

Husky
Moderator/Drawing Help/Testing
Posts: 3313
Joined: Wed May 11, 2011 9:25 am
Location: USA

### Re: Tip - Draw a circle tangent to 3 equal sized circles

clive wrote:To draw a circle tangent to 3 equal sized circles (this ones for you Husky )
Nice! Thank you very much!

Husky
Moderator/Drawing Help/Testing
Posts: 3313
Joined: Wed May 11, 2011 9:25 am
Location: USA

### Re: Tip - Draw a circle tangent to 3 equal sized circles

Hey everybody - just an update on this:

The new version of QCAD pro (3.2.0) has a new circle tool set which provides a perfect solution on this.

Two or three clicks .... and done!!!

You have to test it by yourself - absolute amazing!!!!

Clive
Premier Member
Posts: 1329
Joined: Thu Aug 25, 2011 9:28 pm
Location: UK

### Re: Tip - Draw a circle tangent to 3 equal sized circles

Husky wrote:You have to test it by yourself - absolute amazing!!!!
Yes its brilliant, what would be interesting is if it were possible to select all the solutions offered (in one go)
@Andrew - would this be possible to add in an option for this ? it would make for very interesting pattern making
3 Tangents tool in use.png (18.26 KiB) Viewed 12869 times

caigner
Full Member
Posts: 83
Joined: Wed Jan 30, 2013 5:24 pm
Location: Austria

### Re: Tip - Draw a circle tangent to 3 equal sized circles

I just came back from holidays, installed the new version 3.2 and - WOW!!! The new circle tool is brilliant!Superb!

Thanks alot for all the effort which went into this tool!