You can imagine, if you're studying perfect right triangles, there's no such thing as a perfect right triangle in the universe. These are ideas that we use in geometry, and other things in the universe are really just approximations of these. But to appreciate the philosophical side of Pythagoras, here are some quotes from him, or quotes ascribed to him. There is geometry in the humming of the strings. There is music in the spacing of the spheres. Reason is immortal, all else mortal. And you'll see, even in the 6th century BCE, this thread of Greek thinking, putting reason at a very high level, not just trying to explain everything with pure mysticism.