archaeo Wrote:
-------------------------------------------------------
> Assuming the height is 280 rc!!
Archeo:

You are correct...you must assume a 280 height as dictated by the "base" angular casing...but the width at the apex, as measured by Petrie that confirms Perring's measure, provides us with a lower height for this structure...275 Rc.
Using the 275 calculation then the point where the volume of the lower section is a ratio of 3.14159:1 with the whole structure (as the illustrated shaded red area) would be at a level 32.98Rc above the base...or 12 inches lower than the illustrated 33.58Rc. But still close to center of the entrance passage when this "new" 5:4 (275/220) sloped side is drawn.
And remember...I'm using ten decimal place calculations and rounding the final answer to only two.

Best.
Clive