Egyptians. Don't ask here if you are not looking for answers from others.
Not sure about pryamids, but pyramids are definitely NOT triangles.
No idea. It depends on what you mean by pryamids!
Well we can of course build pryamids. If they could do it in ancient times we can do it in 2013. Back then they didnt have a chainsaw, crane, or chissels. Now we could even probably build it 5x as fast!
Stone
about 80 to 100 roughly!
from 2900bc until 1400bc
Khufu
In the bottom or the dungeons of pryamids or caves.
about 108
Because they decided to
It was decided to build them to protect against Germany building and using them. It was decided to use them on Japan to end the war ASAP and save lives.
Homer Hickam decided to build rockets with his friends in his hometown of Coalwood, West Virginia when he was 14.