Who invented the triangle?

The triangle as a concept is deeply rooted in ancient mathematics and geometry, and there isn't a specific individual credited with its "invention." Early civilizations, including the Egyptians and Babylonians, recognized and utilized the properties of triangles several millennia ago. The concept of a right triangle, in particular, was extensively studied by the ancient Greek mathematician Pythagoras, who is best known for the Pythagorean theorem—though the theorem itself likely predated him.

In modern discussions, such as those on the Lex Fridman Podcast, the idea of "innovating" or conceptualizing the triangle often gets illustrated metaphorically in discussions on innovation and the fundamental role basic shapes and concepts play in building more complex ideas.