In the given triangle, two angles are 30° and 90°, ⇒ Third angle = 60° In a 30-60-90 triangle, the hypotenuse is always twice as long as the side opposite the 30° angle and the side opposite the 60° angle is √3 times as long as the side opposite the 30° angle. The ratio of sides opposite 30°, 60° and 90° angles =1 :√3 : 2 Length of the side opposite the 90° angle = 6 cm ⇒ Length of side opposite the 30° angle =