> Given that the Egyptians didn't use inches or
> feet, can you do this with the royal cubit (which,
> BTW, is 20.6102, not 20.619 inches)?
Well what you should have said, there is no evidence to date to show that they had a cubit that correlates to the inch.
My hypothesis is is that an outside source could have used their cubit of the day in the designing process that when converted back into the sources standard which was equivalent to our modern day inch would reveal all the encoded information.
So to be clear, the Egyptian cubit of their day may have been used in construction , but the designer made sure it could be read and decoded back into a future unit that was the same as the designers unit, doing so would allow the designer to send his knowledge into the future, but then of course the question is, how did he know our present time period would be working with a unit of measure the same as his , my time traveling friend !!.
There are many different cubit lengths that have been discovered , mainly based on body parts, so if you believe the most complicated and precise structure to be built for thousands of years was based on someones arm length then your wellcome to that world, does every one have the exact same length of arm, was it a male, or a females arm, were they young or old when they took the measure,
Check this site out and that highlights at least 16 different cubits and rods, so your 20.6102 is correct and so is my 20.619 , but they are one of many.
Using one of the many cubits available one could have encoded the numbers that i have found.
For example take my suggested figure for G1's perimeter at some 36278" and its mean base side of 9069.5 inches.
Ok so taking one of those 16 possible cubits that are known of, then if one could be found to be 20.6125 then that would fit very nicely and exact into that mean figure , and would go along with the accepted thinking that 440 cubits was the plan for one of the base sides.
As 440 x cubits of 20.6125" = 9069.5"
Then its also pointed out the the height was based on 280 cubits, but not by 20.6125 but by another one of 20.62" rounded.
As my 5773.6" / 280 = 20.62" exactly
Various other cubits are available at all other ancient sites.