need a script for line angle ?

here is a sggestion for a script that would be usefull for mechanical design

add a line and be able in edit mode to change the location of the tips and get the lenght and angle and complement angle for that line possibly in 3D

so you can easily measure angles and lenght in 3d viewport

if anybody can help to make such a script it would be a very good tool to have in blender 2.5

Thanks for any help