This document discusses different types of angles including acute, obtuse, right, and straight angles. It defines an angle as being formed by two rays sharing an endpoint called the vertex. Angles are measured in degrees, with acute angles between 0-90 degrees, obtuse angles between 90-180 degrees, right angles equal to 90 degrees, and a straight angle equaling 180 degrees. It includes examples of each type of angle and encourages identifying them in a game.

1. A N G L E S

2. You will learn to classify angles as acute , obtuse , right , or straight .

3. What is an angle? Two rays that share the same endpoint form an angle . The point where the rays intersect is called the vertex of the angle. The two rays are called the sides of the angle.

4. Here are some examples of angles .

5. We can identify an angle by using a point on each ray and the vertex . The angle below may be identified as angle ABC or as angle CBA; you may also see this written as ABC or as CBA. The vertex point is always in the middle.

6. Angle Measurements We measure the size of an angle using degrees . Here are some examples of angles and their degree measurements.

7. Acute Angles An acute angle is an angle measuring between 0 and 90 degrees. The following angles are all acute angles.

8. Obtuse Angles An obtuse angle is an angle measuring between 90 and 180 degrees. The following angles are all obtuse.

9. Right Angles A right angle is an angle measuring 90 degrees. The following angles are both right angles.

10. Straight Angle A straight angle is 180 degrees.

11. GAME TIME! The object of the game is to be the first to raise your hand and correctly name what type of angle you see . The correct answer will be on the following slide!! Good luck!

13. Acute Angle

15. Obtuse Angle

17. Right Angle

19. Straight Angle

20. GREAT JOB!!