Visible light of wavelength 6000 × 10– 8 cm falls normally on a single slit and produces a diffraction pattern. It is found that the second diffraction minimum is at 60° from the central maximum. If the first minimum is produced at θ1, then θ1 is close to :
(1) 20°
(2) 45°
(3) 30°
(4) 25°