If two adjacent angles are supplementary, they form a ___________.
Define linear pair with figure
We know that the sum of measures of a pair of supplementary angles is .
From the figure we can see that and are adjacent angles.
and form a line or line intersects line at point .
The angle measured on a straight line is equal to
Thus and are adjacent supplementary angles.
Linear pair of angles are formed when two lines intersect each other at a single point or at a common point of intersection.
Hence, two adjacent supplementary angles form a linear pair.