Hi Larry,
not sure if this is what you are trying to achieve but I did this trial with the nodeditor.
Your drawing does not show the top circle in the middle of the 2 bottom circles ?
My method starts with the bend angle required and works out the movement required but
the top circle is in the middle so may not be what you require.
Anyway if its of any use let me know and I will finish it.
Cheers
Barry