A rotation mapping A→B and B→C means A, B, C lie on a circle with equal arc lengths — translate this to equal chord lengths: `dist(A,B)² == dist(B,C)²`.

Also ensure the three points are not collinear: the cross product `(Bx-Ax)*(Cy-By) - (By-Ay)*(Cx-Bx)` must not be zero.

Use squared distances (64-bit integers) for the equality check to avoid floating-point. Collinear points always return "No" regardless of distances.