Aristarchus's method [1] is actually something you can do yourself, and indeed was the historical way the size of the moon was discovered. I personally found t

Aristarchus's method [1] is actually something you can do yourself, and indeed was the historical way the size of the moon was discovered. I personally found that far more satisfying as you're relying on far less complexity to prove the point. [1] https://www.eg.bucknell.edu/physics/astronomy/astr101/specials/aristarchus.html#:~:text=The%20jump%20Aristarchus%20made%20from,measure%20both%20for%20the%20Moon https://www.eg.bucknell.edu/physics/astronomy/astr101/specia....