Constrain to object edge in sketch mode

[willtell11]

Sorry if this is redundant, But I've searched and can't find it.
I need to constrain features in a sketch to the edge of an object.

Again, sorry if this has been covered here or is general knowledge.
OS: Windows 7
Platform: 32-bit
Version: 0.13.1828
Python version: 2.6.2
Qt version: 4.5.2
Coin version: 3.1.0
SoQt version: 1.4.1
OCC version: 6.3.0

[logari81]

hi, yes indeed this question has been answered many times but it doesn't matter. Look below for the answer:
http://www.freecadweb.org/wiki/index.ph ... r_External