Lots of good specifics on the techniques employed - to summarize and add a little.
The pyramids were built on bedrock. Not cooinsedence, but design. Mastabas had been constructed for 500-1000 years previous from just before the 1st dynasty to the 4th and beyond when the Great aPyramid was built. Some knowledge was in the pipe about how much weight a foundation could bear. It was not exact an formulated number, but a feel for the innate properties of materials from years of experience. This phenomenon usually results in “overbuilding” as in the cathedrals of Europe. A pyramid is a classic example of a structure that is over built in that the base is thousands of times greater than needed to erect a structure of such height. However the goal was a pyramid, so of course the base is large.
A flat base was prepared by carving channels in the rock in a grid formation. Water was added. Stone was removed down to the water line or a chalk line made from it. Perfect level, voila.
The essential right angles were established with ropes or rods in a 3x4x5 triangle. The ancients before Pythagoras didn’t know that a2 + b2 = c2, but they knew a 3x4x5 triangle was a right triangle. They made larger or smller versions of this triangle to generate all of their “squares”.
The grid was oriented towards true north by planting a stake in the rock (or rigging up a stand) that was vertical (use a plumb line - as seen in Egyptian drawings). When the shadow was shortest, it is high noon. It is also pointing towards true north at that moment. Use shadows of equal length before and after the noon point to corfirm your measurements.
Stones were rough hewn nearby (see above responses). Labor was provided by the “corvee” a quasi military labor corps that worked like this. “Remeber all that grain we taxed you for in kind? - See how the river is rising now and you can’t work? Would you like to eat? I have grain and you’re broke - come build a pyramid.” Entire families followed the men folk to the corveee and subsisted on the grain stores that the Pharoah had stockpiled. Not slavery, but similar to state socialism.
The river rises and perhaps (my speculation) precut stones were floated to the base of the pyramid or as near as possible. Other techniques are discussed above for pulling stones, many have been tried with some success.
These stones are rough cut with an ingenious method. Make holes or grooves with dolomite balls (yes dolomite balls, and if you don’t believe it, ask the Egyptians what they used). Fill with hot coals (you can use dung, not the best, or the royal store of hardwood from Lebanon, traded for grain, or imported from way up the nile. The Sahara, once a forest had already been decimated long before), add cold vinegar (keeping liquids in unglazed pottery that “sweats” in a shady place makes them cool through evaporation - no high falutin techno theories here, just years of experience in what works) - rocks crack. Voila.
The pyramid has a structure beyond layer over layer - there is essentially an interior pyramid of the largest stones forming a stable core. The smallest stones being the eventual facing on the surface. They came to this idea after several pyramids didn’t make it to opening day due to sides that were too steep, stones that were too loose etc. Also many pyramids did not survive until today due to poor workmanship as well. For those one the board who do not know which these are and will think they do not exist, they are:
The pyramid of Medum (The “False Pyramid”)
The pyramids of Abu Roash and Abusir (ancient Busiris)
The pyramid of Unas
File uder poor architectural design -
The Bent Pyramid
In other words, for the most part only the most perfect pyramids survived in any recognizable state - namely because they were perfect. Egyptian work was as today, subject to the vagaries of expenses, politics, personal and group will power.
Much of the perfect pyramid design was trial and error, not based on theory.
To complete, the stones were dragged up ramps. Work crewes of a hundred thousand on some shifts - working for scores of years. Use a whip as well, and you can get a lot done. Also, no need for a clothing allowance - there were none for the workers.
How was the pyramid made “true” after all of this work? a good question. The proportions of the height of the sides of the great pyramid are the number “phi” (the ease of calculating this proportion is another tale) if the base is considerd to be a measurement of “2”, While working down the pyramid, adding the finishing stones and polishing them to perfection - if any completed portion holds these proportions and this “virtual pyramid” (the area so far completed) is oriented perfectly level, by using water levels, the pyramid will be perfect each step of the way. Approaching the base, a system of rods or rope measures assured that these proportions are followed.
One thing I don’t get here tho - the golden cap stone was said to be put on last, sometimes even after the final polishing to the base. I would think the ramps were removed already. Perhaps it was placed and covered for the inaugural festivities. Also, I am not sure how “polished” the final product was - if there were any footholds to be gained?
As for plans remaining behind. In ancient Greece ONLY ONE extensive template for a column has been found. It is a kind of reddish chalk/paint sketch of a column’s proportions, on its side done on the base of the temple, where steps would eventually be put in. Materials in the ancient world - of any kind - were very expensive. Paper was a final product and not used for “sketches” (not like the modern writer discarding sheets out of the typewrtier after a few failed lines). Through continued practice, memory (over written documentation) was the prefered means of retaining data (the “oral tradition”). Tentative plans were probably made in sand and if any models were made for construction, they were probably just reeds.
The great pyramid was designed and executed by Imhotep a veritable genius, and I suspect much of the complete conception was realized in his head (and his closest adjuvant’s) exclusively until completion.
The argument for “impossibility” (implying extraterestrial or other intervention) based on our own period’s ignorance will only be erased through further exploration. Erik Von Daniken saw evidence of the use of light bulbs in the lack of soot in Egyptian rock tombs from torches. Today, even movies like “The Mummy” and the “Fifth Element” incorporate giant brass mirrors for reflecting sunlight deep into tombs. Today’s mysteries - tomorrow’s pop culture.