In Exercises 1–6, the measure of an angle is given. Classify the angle as acute, right, obtuse, or straight. 𝜋

Key Concepts

Types of Angles

Angles can be classified into four main types based on their measures: acute angles (less than 90°), right angles (exactly 90°), obtuse angles (greater than 90° but less than 180°), and straight angles (exactly 180°). Understanding these classifications is essential for determining the nature of any given angle.

Radian Measure

In trigonometry, angles can be measured in degrees or radians. One complete revolution (360°) is equivalent to 2π radians. Therefore, π radians corresponds to 180°, which is classified as a straight angle. Familiarity with converting between these two units is crucial for angle classification.

Angle Classification Criteria

To classify an angle, one must compare its measure to the standard angle thresholds: less than 90° for acute, exactly 90° for right, between 90° and 180° for obtuse, and exactly 180° for straight. This systematic approach allows for accurate identification of the angle type based on its measure.