With the Circle Options area in the Distance dialog box (Insert | Dimension | Distance), you can use the Add Radius and Subtract Radius options to tell PC-DMIS to either add or subtract the radius of the measured feature to the total distance that is measured. The amount that is added or subtracted will always be along the same vector that calculates the distance. Only one option is available at a time.
A - Normal calculated distance between features
B - Add Radius
C - Subtract Radius
Using the No Radius option does not apply the radius of the feature to the distance measured.