1. Proving Segment Relationships Section 2-7

2. Ruler Postulate The points on any line can be paired with real numbers so that, given any 2 points A and B on the line, A corresponds to zero, and B corresponds to a positive number.

3. Segment Addition Postulate If Q is between P and R, then PQ + QR = PR. If PQ + QR = PR, then Q is between P and R. P R Q

4. Theorem 2.2  Congruence of segments is reflexive, symmetric, and transitive.

5. Pythagorean Theorem In a right triangle, the sum of the squares of the measures of the legs equals the square of the measure of the hypotenuse. a b c