= 3 cos (90° - 38°). cos 38°=3 sin (90°-38°). sin 38°= 3 sin 38° . cos 38° - 3 cos 38° . sin 38°= 0.
In right ABC, right-angled at B. AB = 5 cm and ∠ACB = 30°. Determine the length of the sides BC and AC.