A challenge:

Petrie erred when assuming the sides of G1 being completely encased with imported angular limestone. He believed what others had published before him and the single layer at its base was compelling evidence to support the concept.
Ironically, the builders attempted to assist us “not realizing” that we would incorrectly “assume” the complete structure being encased with these angular stones.
The concept was to “imply” a completed height of angular stones only.
To assist us, they set the first course at a thickness equal to 100th of the calculated height (2.8 Rc) if casing were set in place. It was the simplest means of not having to transport over 50,000 cubic meters of rock across the Nile and Delta for no other reason than to confirm an upper measure of 280 Rc. This measure was required to prove some of the knowledge in the sciences that are displayed within the structure (King’s Chamber)…it had nothing to do with exterior measures.
Petrie returned to Giza to confirm the width of G1 near the apex, as it is viewed today. I believe he was fully aware of another mathematical function of the structure. However, I think he was obliged to remain with the angular casing theory even though he realizes that another ratio existed.
From his confirming measures it is found that G1, without angular casing, was built on a 5:4 ratio. This would produce a height equal to 275 Rc…not the 280 Rc as assumed.
The difference is small, but significant and the designers had to prove that the 280 was an implied height, the 275 being the intended height at the apex and that construction ceasing at 266.7 Rc…because…
They built the Queen’s Chamber to prove it…!
Note:
The following is math and geometry…not art.
Hope those with knowledge of G1 can follow the illustration.


Check course #164

Now the challenge:
With calculator in hand…find the radius of the two.

Best.
Clive