Question

1. what is the sum of an interior angle and its adjacent exterior angle?

360°
30°
90°
180°

Explanation:

Step1: Recall Angle Relationship

An interior angle and its adjacent exterior angle form a linear pair. A linear pair of angles are supplementary, meaning their sum is \(180^\circ\).

Step2: Confirm with Definition

By the definition of adjacent angles on a straight line (linear pair), the sum of two angles forming a linear pair is \(180^\circ\). So the sum of an interior angle and its adjacent exterior angle is \(180^\circ\).

Answer:

180° (the option with "180°")