1. 1.2 Measuring and Constructing Segments

2. Measuring and Constructing Segments
Coordinate- A point that corresponds to only one number on the number line
Postulate (1.2.1) Ruler Postulate: Points on a line can be placed into a one to one correspondence with real numbers on a number line
Distance or length (between two points)- the absolute value of the difference of the coordinates

3. Congruent segments: segments that have the same length
Constructions- a way of creating more precise figures

4. Examples: 2) Construct 2 congruent segments
Pg. 14, Check it Out problem 2

5. Postulate (1.2.2) Segment Addition Postulate- If B is beween A and C, the AB + BC = AC

6. Examples: M is between K and N. 1) KM = 2x-4 MN= 3x KN= 26
2) KM= NM = 4x KN = 8
3) KM= 2x KN = 34

7. Bisects- to cut something in half
Midpoint- a point that divides a segment in half (into two congruent segments)
Segment bisector- a ray, segment, or line that divides a segment in half

8. Constructing Segment Bisectors
Using Paper
Using Compass

9. Examples B is the midpoint of AC
1) AB = 3x + 8 BC = 5x – find x and AC
2) AC= 20x-30 BC = 4x + 2 find x and AB
3) AB = 8x BC = 10x-9 find x and AC