Answer:
Linear pair of angles are formed when two lines intersect each other at a single point. The angles are said to be linear if they are adjacent to each other after the intersection of the two lines. The sum of angles of a linear pair is always equal to 180°. Such angles are also known as supplementary angles.
Explanation:
If there is a pair of adjacent angles, then this pair is a linear pair if the sum of the (measures of the) two angles will be 180°. So, linear pair of angles always add up to 180°. For example, the linear pair of 30° is 150°, the linear pair of 70° is 110°, etc.
These two angles form a linear pair. We have found all four linear pairs of angles. The four linear pairs formed by the intersecting lines ←→QR Q R ↔ and ←→ST S T ↔ are ∠SOQ ∠ S O Q and ∠QOT ∠ Q O T , ∠QOT ∠ Q O T and ∠TOR ∠ T O R , ∠TOR ∠ T O R and ∠ROS ∠ R O S , and ∠ROS ∠ R O S and ∠SOQ ∠ S O Q .