History of Inventions I: Lesson 2 - Pyramids

There have been about 118 original square pyramids they were 480 Feet tall and the sides were 750 long and it weighed about 13 billion pounds and was built with 2.3 million blocks. It takes about 20 years to build one so that would mean they placed 12 blocks per hour day and night. The pyramids had polished limestone covering the whole pyramid but over time it had been stolen or earthquakes shook it off. And at the very top, there was a Benben stone at the top symbolizing their religion. Here is a picture of a dollar bill, I noticed the pyramid and if you look at the top of it, it reminds me of a Benben stone.  

US one dollar bill reverse series 2009jpg
Public Domain, Link

here is a short video that was with this lesson: