hexagon logo

measuring the bottom of a constructed sphere to a plane

Good afternoon,

I am working on a part that requires a theoretical distance from the bottom of a gage ball resting in a tapered cylinder to a datum plane. I have constructed the sphere with the proper diameter and in PC-Dmis, it looks to be in the correct location to get the measurement.

how do I go about dimensioning it where it outputs the distance from plane A to the bottom of the sphere instead of the spheres center?

Thank you kindly in advance.