First I had the simple notion that the trignometric ratios are ratios of sides of a triangle.
But when $\sin(0) = 0 , \cos(0) = 1 $ what do they mean?
I had read about the unit circle definition and I thought that the unit circle definition was just a nice way to represent the triangle inside a circle and in the process simplify the calculation of ratios at various angles.
Am I wrong about the unit circle definition?
Edit 1: After reading the first answer,the next question that came to my mind was, why was the movement of triangles defined that way luckily this was asked before here.
How does the unit circle work for trigonometric ratios of non-acute angles?