1. Warm Up
If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time? Explain.
It’s cheaper to take two friends to the movies at the same time – you are buying 3 tickets. If you take one friend twice, you will buy a total of four tickets.

2. Measuring and Classifying Angles

3. Geometry Vocabulary Angle Vertex Interior of the angle
Chp 1.5
Term
Definition
Picture
Angle
Set of points made up of two different rays connected by the same endpoint. The rays can also be called sides.
vertex
The point where the two rays meet to form an angle
Vertex
Interior of the angle
The area that contains all the points between the sides of an angle
Exterior of the angle
The area that contains all the points outside the angle

4. Ways to Name Angles B ABC CBA 1 Name it by its vertex:
Use a point on each ray and the vertex:
ABC
CBA 1
Use a number, like: 1

5. Geometry Vocabulary Acute angle Right angle Obtuse angle
Chp 1.5
Types of Angles:
Term
Definition
Picture
Acute angle
Measures between 0⁰ and 90⁰
Measures 90⁰
Right angle
Obtuse angle
Measures between 90⁰ and 180⁰
Straight angle
Measures 180⁰

6. Measuring Angles
A protractor can be used to measure angles. Here’s a review: Using a Protractor