1. ANGLES Objective: By the end of this lesson, the students will know the difference between acute, straight, right, and obtuse angles. They will be able to identify these angles with given examples. By: Allison Lantz 3 rd Grade Mathematics (Geometry) Lesson

2. Have you ever looked at a snowflake? Are ALL snowflakes the same? Let’s take a look …

3. Have you ever seen a snowflake like this?

10. Check these out!

11. What do all of these snowflakes have in common?

12. ANGLE S

13. An ANGLE is formed when two rays come together and share a common end point Ray Angle

14. A line has no beginning point or end point. Imagine it continuing indefinitely to both directions. We can illustrate that by little arrows on both ends. A line segment has a beginning point and an end point. All the sides of this triangle are line segments. A ray has a beginning point but no end point. Think of sun's rays: they start at sun and go on forever... Review …

15. What is an angle? Many people think that angle is some kind of slanted line. But in mathematics an angle is made up from two rays that have the same beginning point. That point is called the vertex and the two rays are called the sides of the angle.

16. Types of Angles Right Angle Acute Angle Obtuse Angle Straight Angle

17. 90 degree Angle Where do we see right angles in our environment?

18. Less than 90 degrees Where do we see acute angles in our environment?

19. More than 90 degrees Where do we see obtuse angles in our environment?

20. 180 degrees Where do we see straight angles in our environment?

21. 1. 2. 3. 4. 5. 6.

29.  Everyone will get their own piece of paper and scissors  You will use your scissors to create your own unique snowflake  Once you have created your snowflake, you will share it with the class and point out a few angles that are in your snowflake  Once everyone has made a snowflake, we will hang them up in our classroom to display our work with angles!

30.  Name the four types of angles that we talked about today.  Did your snowflake include any of these angles?  Did we meet our objective? (Objective: By the end of this lesson, the students will know the difference between acute, straight, right, and obtuse angles. They will be able to identify these angles with given examples.)  Tomorrow we will learn about three-dimensional shapes!