One way to know the actual dimensions of the great pyramid would be to ask one of the Extraterrestrial beings that belongs to one of the many ET races that cooperated in its construction as she still has access to database records from that Federation’s database and can easily look up and then explain to us the answers to many of our questions such as this one about dimensions. If you definitively want to know lots of facts about the pyramids of Giza (and other places) then please check out this video with an open mind to the possibility of the information actually coming from a source like the one I mention above.
We only have to but ask the right person(s) regardless of them not being technically of this world (but even that is not necessarily true if their civilisation and its actions pre-date ours, then in that case we are both of this World)!
Pyramid information is just one answer offered and delivered on this amazing YouTube channel (and now also via transcripts of the conversations at this website):
If ever there were two URLs that you should definitely bookmark it should be the two mentioned above…!!
Much love and respect,
Gold Coast, Australia