Pyramids of Giza (no replies)

Mr Hancock’s work has inspired me from a young adult.
His findings of coded numbers in the dementions of the great pyramid
are fascinating. Mr Hancock’s colleague, Robert Bauval, established the mirroring of the three pyramids to the constellation Orion. Meaning that the three are connected.
My question is what are the special attributes of the other two pyramids?
Do they have chambers or dementions of mathematical significants?
The great pyramid echos the earth. What do the other two echo, and more importantly, what do the three represent?

Thanks