A ladder placed against a building is a real life example of a linear pair. Two angles are considered a linear pair if each of the angles are adjacent to one another and these two unshared rays form a line. The ladder would form one line, while a building or wall would form another line.
A linear pair of angles are sometimes simply called supplementary angles. Supplementary angles are angles whose sum equals 180 degrees.
Linear pairs can also be seen in parking lots with diagonally crossing lines running adjacent to a center straight line. While parking lot spaces marked by vertical lines intersecting horizontal lines would create angles, these angles would not be considered adjacent angles due to the sum of their degrees not equaling 180.
Although a linear pair of angles is often used interchangeably to mean supplementary angles, they are not exactly the same. While all supplementary angles do not have to be adjacent, all linear pairs must have adjacent angles that form a line.
Adjacent angles are two angles in a plane that share both a common vertex and a common side, but these sides do not overlap. Other types of angles include vertical angles and congruent angles.