Hi Clive,
An alternative method for a pyramid with the angle of incline of the triangular faces defined by sqd 5 1/2:
Other strategic points within the superstructure can also be determined with a series of simple geometric steps with no numbers involved, after which the drawing can be scaled up to the desired size for the pyramid, and the measurements added.
According to this method, with the sides at the base 440 cubits long, the floor of the sarcophagus chamber is about 82.010 cubits above the base, and the square level at this height has sides of about 311.127 cubits, which is also the length of half the diagonal of the square of the base level (according to Petrie's survey, the floor of the sarcophagus chamber is about 82.050....82.162 cubits above the base).
CT