1. Measure and Classify Angles
1.4 Geometry

2. An angle is created by two rays that have a common endpoint
Angles
An angle is created by two rays that have a common endpoint
Each ray is called the side of the angle. The common
endpoint is called the vertex of the angle. The amount
of rotation about the vertex is called the measure of the angle.
Common units of measurement of angles are degrees and
radians. A B C

3. Parts of an angle A B C
Interior of angle
Exterior of angle
Angles are written with either the vertex point [if no other angles share this vertex] or a point on one of the rays, the vertex, and the point on the other ray.

4. Types of angles Acute Obtuse Right Straight 0o < acute < 90o
90o < obtuse < 180o
right = 90o
Straight = 180o

5. Adjacent angles O A C D DOC is adjacent to COA
DOA is NOT adjacent to COA

6. Protractor Postulate
Each rotation of a ray about a vertex has a unique value between 0 and 180 degrees

7. Angle Addition PostulateC D
If C is in the interior of AOD, then
mAOC + mCOD = mAOD

8. Angle measures