supplementary triangle definition
Supplementary angles are any two angles whose measures sum to 180 degrees. Supplementary angle pairs will either be two right angles (both 90 degrees) or be one acute angle and one obtuse angle. If two angles are both supplementary to the same angle, then the two angles are of equal measure. When two parallel lines are crossed by a third line, the same side interior angles will be supplementary. Any two consecutive angles in a parallelogram will also be supplementary.