### Home > MC2 > Chapter 5 > Lesson 5.3.1 > Problem 5-90

5-90.

**Decide if these angles are acute, obtuse, or right angles. All diagrams are drawn to scale. Homework Help ✎**

a. | b. | c. | d. |

Acute angle: An angle with a measure between (but not including) 0° and 90°.

Right angle: An angle measuring 90°.

Obtuse angle: An angle with a measure between (but not including) 90° an 180°.

To determine the type of angle, use a 90° angle as a reference point.

Since the angle is greater than 90°, it is obtuse.

Acute angle