Which of these four angles is the largest?

Convert everything to degrees: 1 radian = 180°/π ≈ 57.3°, and π/4 radians = 45°. The list is therefore 60°, 57.3°, 45° and 50°, so 60° wins. One radian looks small written down but is nearly 60° — assuming a bare '1' must be the smallest entry is the usual slip.