I have written a set of functions to solve constraint based 2D geometry problems such as finding the intersection points between two circles. These functions are contained in the library 2DGeometryConstraints.scad which can be downloaded from the OpenSCAD folder on my Microsoft OneDrive cloud server: https://onedrive.live.com/redir?resid=625391B4CF1D545D!115&authkey=!AHZ3rqfLOct19dU&ithint=folder%2c I have also included the script 2DGeometryConstraints_examples.scad which graphically demonstrates each of the functions. I hope these prove useful. -Trygon <http://forum.openscad.org/file/n17611/CirclesTangents.png> -- View this message in context: http://forum.openscad.org/2D-Geometry-Constraints-Library-tp17611.html Sent from the OpenSCAD mailing list archive at Nabble.com.