1. Draw a great big circle 3600 miles in radius and find it's area in miles using the approximate for pi 22/7.
= 40,731,428.57 square miles.
2. Find the side of a square with the same area.
= 6382.117875 miles square.
3. Find the volume of a cube with a side 6382.117875 miles.
= 259,952,778,4 cubic miles
This is the volume of the Earth in cubic miles.
4. Find the radius of the Earth from formula; Volume = 4/3 pi radius cubed.
= 3958.618914 miles
5. Know that the perimeter of the Great Pyramid is 1 1/2 minute of 1 degree and there are 360 degrees in a circle so 1 degree.
= 69.11874294 miles
The base perimeter of the Great Pyramid divided by 60 minutes and halved to reach 1 1/2 minute.
= 3041.22469 imperial feet (926.96525 m)
Each side = 760.3061724 imperial feet (231.74131 m). 9123.674069 inches
Petrie mean for socket perimeter = 9125.9 inches gave south side 9123.9 inches.
I think that is pretty close.