No, supplementary angles are not always linear pairs.
Supplementary angles are defined as two angles whose measures add up to 180 degrees. This means that if you have two angles, and their sum equals 180°, they are considered supplementary. However, for two angles to be classified as a linear pair, they must not only be supplementary but also be adjacent and share a common vertex and a common side.
For example, consider two angles that measure 100° and 80°. These angles are supplementary because their sum is 180°. However, if they are not next to each other or do not share a vertex or a side, they do not form a linear pair. In a linear pair, the two angles must be positioned in such a way that they essentially form a straight angle.
In summary, while all linear pairs are supplementary, not all supplementary angles are linear pairs since adjacency is a requirement for a linear pair.