1. Warm Up 09.22.11 Week 6 1) State the postulate that shows the statement to be false: A line contains at least three points.

2. Geometry 2.2 Day 1 I will recognize and use definitions. Definitions Previous knowledge used to explain your answers. Ex 1 A B C D X Is the statement true or false: Explain. D,X, and B are collinear. True. 2 or more points are collinear if they lie on the same line. D,X, and B all lie on DB so they are collinear. Answer

3. A B C D X Do 1: ∠ AXB is adjacent to ∠ CXD False. By definition adjacent angles must share a common side. ∠ AXB and ∠ CXD do not share a common side so they are not adjacent. Answer True or False: 1 st Sentence: True or False 2 nd Sentence: Definition 3 rd Sentence: Describe why definition proves the graph

4. Biconditional Statement A statement that contains the phrase “if and only if”. Ex 3 Three lines are coplanar if and only if they lie in the same plane. Conditional Statement: if three lines are coplanar, then they lie in the same plane. It is a conditional statement and its converse. Converse: if three lines lie in the same plane then they are coplanar.

5. Do: 2 ∠ AXB is vertical to ∠ BXC Assignment: Textbook Page 82, 13 – 23 All and 59 – 68 All. A B C D X