dimensioning a circle that is not a full circle

[mmtech]

Hello,

I have generated some 2D drawings for a project that has cutouts in the door of an enclosure for electrical receptacles. These cutouts are keyed to prevent the receptacles from spinning. So the typical hole looks like this:


What I really want to do is indicate the dimension from the bottom straight line to the top of the circle. I have no way to be sure I'm selecting the very top of the circle. I also find I'm unable to dimension this using a radius value and an arrow.

I think I"m missing something obvious with these difficulties and would appreciate someone pointing me in the right direction.

Best regards,
mmtech

 

[DavidJ]

Choose dimension tool, click the bottom line, click the circle - you should see dialogue



Choose option 1 (line to outside)

 

[mmtech]

Thank you! Likely I was clicking in the wrong sequence.

 

[OTE_TheMissile]

Thank you! Likely I was clicking in the wrong sequence.

That'd be my guess as well. In Alibre, if you click the arc first and the straight line second, it defaults to measuring off the centerpoint of the arc.