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. R P Q

4. Congruence of segments is reflexive, symmetric, and transitive.
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. c a b