1. Geometry
1.4 Angles

2. Angle the common endpoint is called the vertex
a figure formed by 2 rays that have the same endpoint
the rays are called the sides of the angle
the common endpoint is called the vertex

6. Types of angles

7. Angle Addition Postulate
If Point B lies in the interior of AOC,
then m AOB + m BOC = m AOC

8. Angle Addition Postulate PART 2
If AOC is a straight angle and B is any point not on AC then
m AOB + m BOC = 180

9. Measure of an angle
You can use a protractor to find a number associated with each side of an angle.
To find the measure in degrees of an angle, compute the absolute value of the difference of these numbers.

10. Using the protractor
Be sure to line the vertex up on the 0

11. Adjacent Angles
Adjacent angles have…
a common vertex
a common side
no common interior points.

12. Congruent Angles
Congruent angles have the same measure

13. Angle Bisector Definition
An angle bisector divides an angle into two angles of equal measure (congruent)

14. It must be explicitly stated. Examples…
When you look at a figure, you can not assume congruent segments, congruent angles or right angles.
It must be explicitly stated.
Examples…

17. Check for understanding
Please turn to page 20 in your textbook.

18. P. 15 #8-40 (8X)
P. 21 #1-33 odd (protractor)
Look at P. 24 #5-15 odd
Bring a compass on Thursday.
See back board for next assessment.