How to change a reference?
Hi guys I'm new to creo and I'm facing the following problem:
I want to extrude and object so I first have to draw it.
I draw two centerlines, then a rectangle fitted to those centerlines and now I want to place a circle above that rectangle
When I place the circle, it gives me the height between the center of the circle and the top of the rectangle.
I don't want that.
I want the circle to reference the centerline, i.e. the height should be from the center of the circle to the centerline and not to the top of the rectangle.
How do I do that?
Creo 2.0 btw 
Thank you in advance!

