1. Rays and Angles SY
Source: Geometry (2007) by Ron Larson et al

2. Definition Ray: a subset of a line that contains a point
and all points on one side of the line;
ray AB consists of the set of points of line AB that include point A and all
points of the line on the side of B

4. Definition Opposite Rays: two collinear rays that intersect only
at their endpoints

5. Definition
Angle:
a union of two non-collinear rays intersecting only at their endpoints

6. Measure of an Angle

7. Measure of an Angle

8. Postulate

9. Solve for the unknowns:

10. Solve for the unknowns:

11. Solve for the unknowns:

12. Take Note!