Why does OpenGL use degrees instead of radians?

Question

The OpenGL designers were never afraid of mathematics, and knowledge of linear algebra is essential for all but the simplest OpenGL applications. I think it can safely be assume

Answer 1

I'd say that since OpenGL was designed with the end-user in mind, degrees were used because one can specify important angles (90, 180, 270 ...) with integers only, and so there is no need for a floating point GL_PI constant.