1.3: Day 1 - Angles

Homework Review

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?

Math Message

Use the given straws to create an angle.

Be ready to share.

Let’s learn more from BrainPop.

What is an angle?

D O

A angle is two rays or line

segments that share a common endpoint, called

the vertex.

G

Naming AnglesA B

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?

vertex

C

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.

right angle

has a square corner

V

A

E

S

ON

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.

right angle

has a square corner

V

A

E

T

OY

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.

right angle

has a square corner

V

A

E

C O W

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!

Complete MJ page 6 with a partner

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!

Tonight’s HomeworkIn 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.

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