Did you know that triangles have been studied for thousands of years?  ๐
Ancient Egyptians built the 
Pyramids using triangles. The famous mathematician 
Pythagoras (circa 570-495 BC) discovered many triangle properties and the 
Pythagorean theorem, which explains relationships between triangle sides.  ๐
Archimedes, a great mathematician from ancient Greece, also studied triangle areas. In Asia, the Indian mathematician 
Brahmagupta (598-668 AD) worked with triangle areas too! Today, we still use ideas from these brilliant minds in math and engineering. How cool is that?  ๐