1. Splash Screen

2. 1.2 linear measure
Honors Geometry

3. Lesson Menu Five-Minute Check (over Lesson 1–1) CCSS Then/Now
New Vocabulary
Example 1: Length in Metric Units
Example 2: Length in Standard Units
Key Concept: Betweenness of Points
Example 3: Find Measurements by Adding
Example 4: Find Measurements by Subtracting
Example 5: Write and Solve Equations to Find Measurements
Key Concept: Congruent Segments
Example 6: Real-World Example: Congruent Segments

4. 5-Minute Check 1 Name three collinear points. A. A, B, Q B. B, Q, T
C. A, B, T
D. T, A, Q
5-Minute Check 1

5. What is another name for AB?
A. AA
B. AT
C. BQ
D. QB
5-Minute Check 2

6. Name a line in plane Z.
A. AT
B. AW
C. AQ
D. BQ
5-Minute Check 3

7. 5-Minute Check 4 Name the intersection of planes Z and W. A. BZ B. AW
C. AB
D. BQ
5-Minute Check 4

8. 5-Minute Check 5 How many lines are in plane Z? A. 2 B. 4 C. 6
D. infinitely many
5-Minute Check 5

9. 5-Minute Check 6 Which of the following statements is always false?
A. The intersection of a line and a plane is a point.
B. There is only one plane perpendicular to a given plane.
C. Collinear points are also coplanar.
D. A plane contains an infinite number of points.
5-Minute Check 6

10. Objectives Use segment postulates.
Use the Distance Formulas to measure distances as applied.
Determine precision and measurement.

11. CCSS Content Standards
G.CO.1 Know precise definitions of angle, circle, perpendicular line, parallel line, and line segment, based on the undefined notions of point, line, distance along a line, and distance around a circular arc.
G.CO.12 Make formal geometric constructions with a variety of tools and methods (compass and straightedge, string, reflective devices, paper folding, dynamic geometric software, etc.).

12. Then/Now You identified and modeled points, lines, and planes.
Measure segments.
Calculate with measures.

13. Postulate: The Ruler Postulate
For any point on a line there is exactly one number that corresponds to that point called the “coordinate”
Points
A B
a b
Coordinates

14. Distance on a Number Line
The distance between points A and B written as AB, is the absolute value of the difference between the coordinates of A and B (a , b).
AB is also called the measure of AB. A B a b
AB = | a – b | or | b – a |

15. Ex. 1: Finding the Distance Between Two Points
Examples: Find The Following
BD =
AD =
CD =

16. Definition segment- an infinite set of points consisting of two points called endpoints and all the points between them.
* Named by its endpoints: segment AB, AB A B

17. Concept

18. Find Measurements by Adding
Example 3:
Find Measurements by Adding
Find XZ. Assume that the figure is not drawn to scale.
XZ is the measure of XZ. Point Y is between X and Z. XZ can be found by adding XY and YZ.
___

19. Add.

20. Find BD. Assume that the figure is not drawn to scale.
16.8 mm
50.4 mm
A mm
B mm
C mm
D. 84 mm

21. Postulate: Segment Addition Postulate
If point Q is between points P & R then: PQ + QR = PR
x + 9 2x P Q R 30
Find PQ, QR and x:

22. Definition of Congruent segments
“Two segments are said to be congruent if and only if they have the same measure.”
There is a phrase “if & only if” which means that the definition is two way or (bi-conditional).
1) If the segments are congruent, then they are equal.
2) If the segments are equal, then they are congruent.

23. A C
10 cm
10 cm B D

24. HOMEWORK:
Pgs
# 5-8
# 14-19
# 21-33, 39
# 46-50

25. Linear Measure and Precision
Section 1-2 part 2

26. 1.2 Linear Measure and Precision
Objectives: Measure segments and determine accuracy of measurement.
Compute with measures.

27. Measuring Line Segments
Unlike a line, a line segment, or segment, can be measured because it has two endpoints. The length of a segment is only as precise as the smallest unit on the measuring device.

28. Measuring Line Segments
The PRECISION of any measurement depends on the smallest unit available on the measuring tool. The precision of a measuring device is calculated by taking of the smallest increment of measure of the measuring device.
Ruler 1:
Ruler 2:

29. Probability and Segment Measure
Probability (P) of an event =
The probability that a point randomly selected on segment AD is contained in with a measure of 2 is
2 mm
6 mm
2 mm A B C D

30. Precision Describes how accurate a measuring tool is
For the tape measure, the smallest unit was 1/16th of an inch
For the metric ruler, the smallest unit was 0.1 cm = 1 mm

31. Precision (con’t)
If we measure using the metric ruler, and get a length of 4.7 cm, this means the precision = cm and the actual length is somewhere between cm and 4.75 cm
If we get a length of 12 ½ inches using the tape measure ( ½ = 8/16), then the actual length is between 12 15/32 and 12 17/32

32. Line Segment (segment)
Portion of a line with two endpoints
Labeled without arrowheads: AB
Can be measured since it has endpoints
Include units of length when measuring

33. Assignment
Pp #12-48
Do #12 – 15 now