1. Chapter 2, lesson 5: A Simple proof
SWBAT:
Identify postulates, axioms, and theorem to justify statements in a proof
Use theorem to solve geometric problems

2. 1. Vertical angles are equal. 2. Postulate 4, right angles are equal.
List as many reasons as you can that prove that all four angles are right angles.
1. Vertical angles are equal.
2. Postulate 4, right angles are equal.
3. Each of the adjacent angles to the measured right angle must also be a right angle because the adjacent angles are supplementary. Therefore, the vertical angle must also be a right angle because it is adjacent and supplementary to those angles.

3. 1. Vertical angles are equal
2. Axiom 5, whole is greater than the parts
3. Axiom 5, whole is greater than the parts
4. Axiom 3, equals subtracted from equals are equal

4. 5-6. vertical angles and right angles are equal
7. adjacent and supplementary angles and things that are equal to the same thing are equal to each other (Axiom 1)
8. vertical angles are equal and equals subtracted from equals (Axiom 3)