In a right triangle if one angle is 30° what is the other acute angle?

Explanation: Sum of angles = 180°. With 90° and 30° the third angle = 180°-90°-30° = 60°. The 30-60-90 triangle has side ratios 1:√3:2 and is one of the most important special triangles in mathematics. It appears extensively in trigonometry geometry and physics problems in all levels of competitive examinations.