Drawing sphere touching (not cutting) 3 surfaces / lines

[twhao123]

Dear Sir/Ms,

How do I draw a sphere that is touching (not cutting) three surfaces/lines?

There is a plugin to do trilateration but it requires three known points. However, instead of points, I would like to do the same but for lines and surfaces (including curved surfaces).

I am trying to draw spheres for lightning protection.

Thank you.