They would topple over otherwise!
Because they believed that they would offend the gods if they did not face east
North
the Nile river.
It can, but pyramids don't necessarily have to have a square face.
North
Pyramids are tombs. The egyptians wanted the pharaoh to have a good after life. That's why the four walls point to the sky.
The answer is yes the pyramids only faced the north in egypt.
Four face.
north
They faced the pyramids, otherwise they would have been working behind their backs!
The pyramids were built as a tomb for the pharaoh and his/her family. The pyramids were shaped as a pyramid because it pointed to the sky and to Aryans belt (the three Star's three kings)). The sky was where the afterlife was so the pyramid pointed to it also the pyramid also mirrored the stars because they believed that the stars were gods from the heavens above. The pyramids was a place for the pharaoh to travel to the afterlife.
No one "discovered" it, just like no-one "discovered" the sky. Anyone who has the faintest idea where "Giza" is already knows about the pyramids.