1. 1.3: Day 1 - Angles

2. Homework Review

3. What is the value of the digit? Write your answer on your slate.
Mental Math
What is the value of the digit?
Write your answer on your slate.
What is the value of the 6 in 67?
What is the value of the 9 in 903?
What is the value of the 4 in 1,416?
What is the value of the 2 in 3,128?
What is the value of the 4 in 14,002?
What is the value of the 3 in 346,041?

4. Math Message Use the given straws to create an angle.
Be ready to share.
Let’s learn more from BrainPop.

5. What is an angle?
A angle is two rays or line segments that share a common endpoint, called the vertex. D O G

6. Naming Angles How to name angles: A B C
vertex A B C
How to name angles:
The vertex is one way to name an angle. See above – the angle could be named B because B is the vertex of the angle.
Remember that the middle letter in the name of the angle is always the vertex – it is a VERTEX SANDWICH
Is angle CBA a way to name this angle? Why or why not?
How about angle BAC? Why or why not?

7. Let’s make different types of angles with our straws!
An acute angle is an angle that is smaller than a right angle.
Try it: first create a right angle. Then move one of the straws to make the angle smaller than the right angle. S O N A
right angle
has a square corner V E

8. Let’s make different types of angles with our straws!
An obtuse angle is an angle that is larger than a right angle.
Try it: first create a right angle. Then move one of the straws to make the angle larger than the right angle. T O Y A
right angle
has a square corner V E

9. Let’s make different types of angles with our straws!
A straight angle is an angle that looks like a line or line segment with three points.
Try it: first create a right angle. Then move one of the straws to make the angle straight. O W C A
right angle
has a square corner V E

10. Important ideas to remember about angles
Angles can be formed by two rays or two line segments that share a common endpoint
The common endpoint is called the vertex
The vertex is always named in the middle of an angle
When you draw an angle, make sure you use a half circle to show the viewer where to look
This shouts, look here!

11. Complete MJ page 6 with a partner

12. Wrap it UP! Go on an angle scavenger hunt with a partner:
Find one acute angle
Find one right angle
Find one straight angle
Find one obtuse angle
Be ready to share!

13. Tonight’s Homework In your Math Notebook, define, draw and label
a point
a line
a line segment
a ray
an angle
an obtuse angle
an acute angle
a right angle.

14. Math Boxes