u/AdScared4138

So I am working on my extended essay and euclidian and non-euclidian geometry, and I can barely find any good sources other than wikipedia (which I doubt IB accepts as an academic source. My question is "How does Gaussian curvature distinguish between Euclidean, spherical, and hyperbolic geometries, and what are the mathematical implications for triangle angle sums?", and I also just would like some general insight on this kind of math as I am relatively new to it.