1. Bellwork
Solve for x
Find three cities on this map that appear to be collinear

2. Bellwork Solution
Solve for x

3. Bellwork Solution
Find three cities on this map that appear to be collinear

4. Use Segments & Congruence
Section 1.2

5. The Concept
Today we’re going to discuss the concept of measurement of line segments
We have to be aware that segments are the only line derivations that can be measured

6. Definitions Postulate Rule that is accepted without proof
Can also be called an axiom
Rule that is accepted without proof
Postulate
1.2
Axis of symmetry
Vertex

7. Ruler postulate
This postulate explains that two points on a line can be explained as two coordinates
The distance between the two coordinates correlates to the length of the segment A B x1 x2

8. Ruler Postulate uses One use is if we assign values to the coordinatesB
(2,0) x1
(12,0) x2
Or it can be used to allow the use of a ruler to find the length of a segment
Seems nonsensical, but again is something that must be explained in order to base further exploration

9. Segment Addition Postulate
This postulate explains that two connected segments created by a point between two others can be added together to get the full distance
It can also be used to explain interior points
If B is between A & C then AB+BC=AC
If AB+BC=AC, then B is between A and C A B C

10. Segment Addition Postulate use
Based on this postulate find the length of BC, if AC=32 A B C 13

11. Congruence Congruence The same measure as AB is congruent to CD
Written as
Important that congruence is used in lieu of equals

12. Nomenclature This denotes the segment AB
At this point we should also discuss the two different nomenclatures you may see regarding segments
This denotes the segment AB
This denotes the length of segment AB

13. Use of Congruence Given the following points are XY and WZ congruent?

14. Homework
1.2
1, 2, 7-10, even, 21-35, odd

15. Example Point S is between R and T on RT. Find RS & ST RS=2x-8
ST=3x-10
RT=17

16. Most Important Points Definition of Postulate Ruler Postulate
Segment Addition Postulate
Definition of Congruence