How do i draw? Perfect Cirlce, Square Equilateral Trianles Polygons

[Alan Horkan <horkana tcd ie>]

> I just realised that middle clicking allows you to add a corner to 
> polygons and polylines, ill definately have to update the 
> documentation (im just not used to having a middle button, i wonder 
> how MS windows users get around i that?)

And for some objects middle click says no object menu

Aside from using "Snap to Grid" to draw perfect cirles and squares i 
have not figured out how to do equilateral polygons and triangles.  I 
thought i might be able to write a custom sheet to do this or there 
might be a better way im just not aware of.  
Is it currently possible?

Perhaps an object menu would be a good way to access a constraint and 
set the sides to be fixed as equal length.  
(ive just read the faq again and im reasonably sure this is not 
available in the manual but the manual is not one the dia webpage and i 
dont have an uptodate copy of dia on this particular machine)

Thanks in advance
Alan