Examples of Different Types of Angles (Acute, Obtuse, Right Explained)

📚 Quick Study Guide

📐 Angle Basics:
• 📏 An angle is formed by two rays sharing a common endpoint, called the vertex.
• 🧮 Angles are typically measured in degrees (°).

📐 Types of Angles:

• 锐角 Acute Angle: An angle measuring between 0° and 90° ($0 < x < 90$).
• 钝角 Obtuse Angle: An angle measuring between 90° and 180° ($90 < x < 180$).
• 正角 Right Angle: An angle measuring exactly 90° ($x = 90$).
• 平角 Straight Angle: An angle measuring exactly 180° ($x = 180$).
• 🔄 Reflex Angle: An angle measuring between 180° and 360° ($180 < x < 360$).

Practice Quiz

1. What type of angle measures 45°?
1. Acute
2. Obtuse
3. Right
4. Straight
2. Which of the following is an obtuse angle?
1. 30°
2. 90°
3. 120°
4. 180°
3. A right angle measures:
1. Less than 90°
2. Greater than 90°
3. Exactly 90°
4. 180°
4. Which angle is greater than a right angle but less than a straight angle?
1. Acute
2. Obtuse
3. Right
4. Reflex
5. What type of angle is formed by the corner of a square?
1. Acute
2. Obtuse
3. Right
4. Straight
6. An angle measuring 179° is a(n):
1. Acute angle
2. Right angle
3. Obtuse angle
4. Straight angle
7. Which of these angles is NOT an acute angle?
1. 1°
2. 45°
3. 89°
4. 91°