1. 2.6 Proving Angles Congruent
A theorem - a conjecture or statement that you prove true.
Theorem 2.1 – Vertical Angles Theorem
Vertical angles are congruent.

2. Using the Vertical Angles Theorem
What is the value of x?
2x + 21 = 4x
21 = 2x
10.5 = x

3. Congruent Supplements Theorem
If two angles are supplements of the same angle (or of congruent angles), then the two angles are congruent.
If and are supplements and and are supplements, then

4. Theorems Theorem 2.3 – Congruent Complements Theorem
If two angles are complements of the same angle (or of congruent angles), then the two angles are congruent.
Theorem 2.4 – All right angles are congruent.
Theorem 2.5 – If two angles are congruent and supplementary, then each is a right angle.

5. More Practice!!!!!
Classwork – p. 124 – 127 #6 – 12, 16, 17, 20 – 22, 26 – 29, 33 – 35 ALL.
Homework – Finish classwork.