If you draw a big enough right triangle on the Earth, it will visibly fail to satisfy the Pythagorean theorem. The geometry of the Earth is approximately spherical geometry, not Euclidean geometry.
Euclidean geometry is a set of principles and conclusions for flat space. That Earth is not flat in no way makes Euclidean geometry inaccurate.
If you draw a big enough right triangle on the Earth, it will visibly fail to satisfy the Pythagorean theorem. The geometry of the Earth is approximately spherical geometry, not Euclidean geometry.
Euclidean geometry is a set of principles and conclusions for flat space. That Earth is not flat in no way makes Euclidean geometry inaccurate.