I am not an engineer or even a mathematician, but I find the "built by slaves" concept hard to swallow. Not because of some ingrained aversion to further degradation of African history either, I find the craftsmanship and structures shockingly complex for the simple purpose of burial.
Yosemite, I must own up and make a mea culpa here. After posting my initial reply I did some research and found out that the long standing assertion that the pyramids were built by slaves has been called into question. There were smaller pyramids located nearby that were used as tombs for those who worked on the pyramids
and as for how they were constructed, the answer may be less complicated than typically asserted:
as for their purpose, who knows?
Americans are more aware of the constant attempt by the academic community to protray Egypt as a non-African civilization. Therefore, Black Americans just been a little more vocal about the appropriation of Egypt. Most Afrocentric scholars of good faith are simply trying to rewrite the wrongs. It's important to note that there are black African scholars who argue the same issue.
I'm not an Egyptologist but I do know that the pyramids were not build by slaves because there is no archeological evidence to support that notion. In fact, the archeological proves otherwise. According to Egyptologists, pyramids were build for the king to serves a tomb.