Selecting part of surface
I am trying to select part of a surface but Creo 2.0 only selects the whole surface across the boundary.
You can see this from the images below: The first one shows a seingle surface selected, and the second the Intent Surface. Both surface cross the the ledge, but all I want is the thin strip towards the top of hte image. I've tried trimming the surface using the corner line, but even though Creo correltly creates an intersected line, it won't trim successfully using this line.


I presume there is a way to do it using Creo's rather unintuituve surface selection using various combinations of ctrl and shift, but I can't figure it out.
Help would be appreciated,
Sam

