A linear pair of angles, is formed when two lines intersect. Supplementary are two angles that add up to 180, so yes, they do in fact form a linear pair.
Supplementary angles and linear pairs both add to 180°. Two angles may be supplementary, but not adjacent and do not form a linear pair. If two angles are adjacent and do not equal 180°, then they are not supplementary and do not form a linear pair.
