Question

1.11: swbat measure and classify angles as acute, obtuse, or right using their degree measure. directions: complete the following questions by showing all work and annotations. keep work organized and box any final answer. all work must be shown in order to receive full credit. for #s 1 - 3, classify the angles as acute, obtuse, right, or straight: #1.) 130° *#2.) 90° #3.) **#4.) name the angle below using proper notation and classify it: ∠mon 60° challenge: if a circle is 360°, explain why a straight line is 180°. 360°

Explanation:

Step1: Recall angle - type definitions

An acute angle has a measure between 0° and 90°, a right - angle measures 90°, an obtuse angle measures between 90° and 180°, and a straight angle measures 180°.

Step2: Classify angle in #1

The angle in #1 measures 130°. Since 90° < 130° < 180°, it is an obtuse angle.

Step3: Classify angle in #2

The angle in #2 measures 90°. So it is a right angle.

Step4: Classify angle in #3

The angle in #3 is a half - circle, which measures 180°. So it is a straight angle.

Step5: Name and classify angle in #4

The angle can be named as ∠MON. Since 0° < 60° < 90°, it is an acute angle.

Step6: Explain why a straight line is 180°

A circle is 360°. A straight line is a half - rotation. Since a half - rotation of a full 360° circle is $\frac{360^{\circ}}{2}=180^{\circ}$, a straight line is 180°.

Answer:

#1. Obtuse angle
#2. Right angle
#3. Straight angle
#4. ∠MON, Acute angle
Challenge: A circle is 360°. A straight line is a half - rotation of a circle, so it is 180°.