1. Learn to name and identify parts of an angle.
Applied Geometry
Lesson: 3 – 1
Angles
Objective:
Learn to name and identify parts of an angle.

2. Ray
What is a ray?
Opposite rays: two rays that are part of the same line and have only their endpoints in common.

3. Angle
Angle: a figure formed by two noncollinear rays that have a common endpoint and are not opposite rays.
Vertex: the common endpoint
Sides: the two rays that make up the angle

4. Angle… What if the rays were collinear?
What would the angle look like? A B C
Straight angle: the figure formed by opposite rays.

5. Naming Angles More than one way to name:
Name by letters (follow the lines)
Vertex is always middle letter
Name by vertex
*Warning* Only use if there is one angle
Name by number (only if given)

6. Name the angle in all ways

7. Example Name the angle in four ways
Example Name the angle in four ways. Then identify its vertex and its sides.
Vertex: B
Sides:

8. Name the whole angle in as many ways as possible
Cannot use vertex to name because there are 3 angles with
vertex P not one.
Cannot use number to name because there is not a number that
represents the whole angle.

9. Name all angles having W as their vertex.
Do not name the same angle twice.
Not asking for the different ways to name, just asking for angles.

10. Name all angles having W as their vertex.

11. Name all angles having W as their vertex.

12. Parts of an angle An angle separates a plane into three parts
Interior of the angle
Exterior of the angle
On the angle itself

13. Tell whether each point is in the interior, exterior, or on the angle.

14. Homework
Pg – 8 all, 10 – 32 E