Peripheral, but pertinent to your understanding Bill. As part of his TLAR
exercise, Tom Knauff suggests this.

You are approximately two (of your) paces tall. Mark a spot and take ten
paces. Look back at the angle. That's 1/5 from your eyes to the spot.
Take 30 more paces and you have 1/20. Now try 30, 40, and even 60/1 if you
have the room. Gives a bit of meaning to the ratios.

TLAR stands for "That Looks About Right".

Frank Whiteley