How do I calculate the size of ArcHandles?

I read the documentation for ArcHandles but couldn’t find a property that provides the size for them.


Basically, I’m wondering how to calculate the value of x.

It’s not as simple as adding a specific number to the longest side of the part because it seems to change with increased size.


Oh, also in the first image x is around 9.8 and in the second image x is around 54.2. I found that out by duplicating the part and scaling it until its touching both of the orbs.