1. Section 1.2 – Use Segments and Congruence
In Geometry, a rule that is accepted without proof is called a postulate or axiom.
A rule that can be proved is called a theorem.

2. Section 1.2 – Use Segments and Congruence

3. Section 1.2 – Use Segments and Congruence
ADDING SEGMENT LENGTHS
When three points are collinear, you can say that one point is between the other two.

4. Section 1.2 – Use Segments and Congruence

5. Section 1.2 – Use Segments and Congruence
Example 1:
The cities shown on the map lie approximately in a straight line. Use the given distances to find the distance from Lubbock, Texas, to St. Louis, Missouri.

6. Section 1.2 – Use Segments and Congruence
Example 2:
Use the diagram to find GH.

7. Section 1.2 – Use Segments and Congruence
CONGRUENT SEGMENTS
Line segments that have the same length are called congruent segments.

8. Section 1.2 – Use Segments and Congruence
Example 3:
Plot J(-3, 4), K(2, 4), L(1, 3), and M(1, -2) in a coordinate plane. Then determine whether Segment JK and Segment LM are congruent.

9. Section 1.2 – Use Segments and Congruence
Example 4:
Point S is between R and T on Segment RT. Use the given information to write an equation in terms of x. Solve the equation. Then find RS and ST.
RS = 3x – 16
ST = 4x – 8
RT = 60

10. Section 1.2 – Use Segments and Congruence
Example 5:
Point B is between A and C on Segment AC. Use the given information to write an equation in terms of x. Solve the equation. Then find AB and BC.
AB = 4x – 5
BC = 2x – 7
AC = 54