1. 2.5 Postulates and Paragraph Proofs
Obejctives: Identify and use basic postulates about points, lines, and planes.
Write paragraph proofs.

2. Refer to Handout
Postulate 2.1 through 2.7

3. Theorem
A statement or conjecture (educated guess) that has been shown to be true
Can be used to show that other statements are true
Example: If M is the midpoint of AB, then AM = MB. A M B

4. Proof
Logical argument in which each statement is supported by a statement that is true
One type of proof is a paragraph proof – you simply write a series of statements explaining why a conjecture is true

5. Four Essential parts of a good proof:
State the theorem or conjecture to prove.
List the given information.
If possible, draw a diagram to illustrate the given information.
Develop a system of deductive reasoning.
Deductive reasoning = making conclusions based on what you already know

6. Determine the total number of segments that can be drawn.

7. Assn: p. 108 #8 - #20