It is estimated that construction took between 14 and 20 years, around 2560 BC.
Modern estimates put it at 14-20 years (c.2589-69BC) According to the ancient Greek historian Herodotus who lived c.450BC, 100,000 men were employed in its construction. Just think the pyramid was...
20 years
it took 20 years
the great pyramid of Pharaoh Khufu for example, took 100,000 slaves and 20 years to do it