You could well be right that the Egyptian didn't use trig or even decimal
but their building certainly implies an understanding of basic arithmetic
and algebra. There are many ways to arrive at the answer to math problems
by using simpler math. Before the calculus people still needed to solve
problems which were in effect, calculus.

It would seem apparent that the pyramid builders used geometry, algebra, and
simple math. Whether any of this was The message or even A message might yet
remain to be proven.

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Man fears the pyramid, time fears man.