Final answer:
Adjacent angles that are not a linear pair share a common side but don't form a straight line.
Step-by-step explanation:
Adjacent angles that are not a linear pair are angles that share a common side but don't form a straight line. They are not opposite each other, and they do not add up to 180 degrees.
For example, let's consider the angles formed by two intersecting lines. The angles on the same side of one line and different sides of the other line are adjacent angles that are not a linear pair.
These angles are often called adjacent complementary angles if their sum is 90 degrees, or adjacent supplementary angles if their sum is 180 degrees.