Supplementary angles are a pair of angles in geometry that add up to a total of 180 degrees when combined. In other words, if you have two supplementary angles, the measure of the first angle plus the measure of the second angle equals 180 degrees.
Mathematically, if two angles are labeled as ∠A and ∠B and they are supplementary, it can be expressed as:
∠A + ∠B = 180 degrees
Supplementary angles are often used in various geometric and trigonometric calculations. When two lines intersect, the angles opposite each other (forming a "Z" shape) are supplementary. For example, in the case of a straight line, the angles on either side of the line are also supplementary, totaling 180 degrees.