1. 2-5 Proving Angles Congruent

2. Vertical Angles
Angles formed
by opposite rays.

3. Adjacent Angles Angles that share a common side and a common vertex,
but have no common interior points.

4. Complementary Angles
Two angle whose measures have a sum of 90 degrees. or

5. Supplementary Angles
Two angles whose measures have a sum of 180 degrees. or

6. Identify the Angles
Name a pair of vertical angles. Name a pair of adjacent Angles. Name a pair of complementary angles. Name a pair of supplementary angles.

7. Looking at a Diagram When looking at a diagram, we can conclude:
Vertical angles
Adjacent angles
Adjacent supplementary angles

8. We cannot assume: Angles or segments are congruent
Angles are right angles
Lines are parallel or perpendicular
(unless there are marks that give this information)

9. What can you conclude from the diagram?

10. Angle Investigation Draw two intersecting lines.
Number the angles as shown.
Use a protractor to measure each angle.
Make a conjecture about vertical angles.

11. Find the value of x

12. Find the value of x

13. Congruent Complements Theorem
If two angles are complementary to the same angle (or congruent angles), then the two angles are congruent.

14. Congruent Supplements Theorem
If two angles are supplementary to the same angle (or congruent angles), then the two angles are congruent.

15. All right angles are congruent.

16. Congruent and Supplementary

17. Find the value of both variables.

18. Find the value of x.

19. Find the measure of each angle.

20. Find the measure of each angle.
m1 m2 m3 m4