Okay, I got the 'kids' tucked in and the sky was clear....
TeeDee, re the picture you referenced:
The left side UCR measured 38.5", toggle to toggle. The tree strap measured 7.5" from the limb to the toggle.
The right side UCR measured at 68.5", toggle to toggle. The porch side strap measured 9.5" from pillar to toggle.
The ridge line measured 98.5". My end channel loops are shorter than I'd played with before, but I also have a little more sag than usual at the moment.
Distance between the pillar and the limb is about 195" -- 6-1/2 steps based on a 30" nominal stride. (I marched a lot in college)
Height of the limb is about 70"; height of the strap at the pillar is about 77". (guestimated; I'm 74" tall).
The ridge line is also essentially level.
I believe that, with gravity as a constraint, establishes the geometry. I can get more precise later if you need that level of detail.