There is so very little recorded about the Great Pyramid
builders regardless of what era one believes it was built
that it might be unrealistic to expect much of their math
to have survived. Knowledge of pi might have even been a
builders' trick which was very lightly recorded and hasn't
survived.

Since their calender was off they might have used movable
(wooden) markers or structures around the pyramids to com-
plete their function as a time keeper.

Whatever the truth it seems that we should be seeking the
whole picture from all angles.

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Man fears the pyramid, time fears man.