Problems with dimenioning - is it possible to extend a circle on a drawing?

[simonsp]

Hi,

I have difficulties with making a 12mm dimension line for where the line would have crossed the circle if it had been whole.
I have attached to pics of what happens when I try to make my dimension, and what I want.

Is it possible to extend the circle Or in any other way to achieve my goal.

I have tried to draw a circle onto the drawing, but that does not update if I change the diameter of 173.




Thanks

 

[MrCATIA]

Simon, could you better explain what you are trying to do. I've looked at all three of the attached images, and I don't understand your question. thanks.