According to historical analysis the ancient Egyptians built the Giza Pyramids; Khufu, Khafre and Menkaure in a span of 85 years somewhere between 25 BC.
Scorpion I was the first of two kings so-named of Upper Egypt during the Protodynastic Period. How the Pyramids were built is a source of speculation and debate.
The age of the Pyramids of Giza is an uncertainty, as archaeologists cannot place the construction of these incredible monuments to a specific date.
Radio carbon dating determines the age of ancient objects by means of measuring the amount of carbon-14 there is left in an object.
A man called Willard F Libby pioneered it at the University of Chicago in the 50's. This is now the most widely used method of age estimation in the field of archaeology.
According to conventional Egyptian chronology, the Egyptian civilization coalesced around 3150 BC, when upper and lower Egypt were unified under the rule of one Pharaoh.