1. Postulates and Paragraph Proofs Section 2-5

2.  postulate or axiom – a statement that describes a fundamental relationship between the basic terms of geometry. Postulates are accepted as true.  proof – a logical argument in which each statement you make is supported by a statement that is accepted as true.  theorem – a statement or conjecture that has shown to be true.

3. Postulates  2.3 A line contains at least 2 points.  2.4 A plane contains at least 3 points not on the same line.  2.5 If 2 points lie in a plane, then the entire line containing those points lies in that plane.

4.  2.6 If 2 lines intersect, then their intersection is exactly one point.  2.7 If 2 planes intersect, then their intersection is a line.

5. Midpoint Theorem (2.8)  If M is the midpoint of, then A M B

6. 5 Parts of Good Proof  State theorem or conjecture to be proved.  List the given information.  Draw a diagram if possible.  State what is to be proved.  Develop a system of deductive reasoning.