Are Cartesian coordinates considered to be curvilinear coordinates?

Question

In the wikipedia page on curvilinear coordinates it is said:

"Well-known examples of curvilinear coordinate systems in three-dimensional Euclidean space (R^3) are Cartesian, cylindrical and spherical polar coordinates."

Is this generally accepted as correct?

Answer 1

Yes. "Curvilinear" means that the coordinate lines are allowed to be more general curves, but they can also just be straight lines.