Question

1. why is the sum of an exterior angle of a polygon and its adjacent interior angle equal to 180°? they are complementary angles they are vertical angles they are a linear pair. they are corresponding angles.

Explanation:

An exterior angle and its adjacent interior angle of a polygon form a linear pair. By the definition of a linear pair, the sum of their measures is \(180^\circ\) (since a straight line is \(180^\circ\)). The other options: complementary angles sum to \(90^\circ\), vertical angles are equal but not necessarily summing to \(180^\circ\), and corresponding angles are related in parallel - line - cut - by - transversal situations and don't necessarily sum to \(180^\circ\) in this context.

Answer:

They are a linear pair.