1. Bell Ringer on Lesson 1-1 - 6 questions In your notes, then do p. 11-12 53, 58, 61 and 63

2. Watch Video - Describing What You see.

3. 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.). Mathematical Practices 6 Attend to precision.

4. Then/Now You identified and modeled points, lines, and planes. Measure segments using equations and calculate with measures with a 90% accuracy.

5. Vocabulary line segment betweenness of points between congruent segments construction

6. Example 1 Length in Metric Units B. Find the length of AB using the ruler. Each centimeter is divided into fourths. Point B is closer to the 4.5 cm mark. Answer: AB is about 4.5 centimeters long.

7. Example 2 Length in Standard Units B.

8. Example 2a A. B. C. D.

9. Concept

10. 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. ___

11. Example 3 Find Measurements by Adding Add.

12. Example 3 Find BD. Assume that the figure is not drawn to scale. B C D 16.8 mm 50.4 mm

13. 3 minutes Individual Practice p. 18 – 20 1, 2, 13, 15,

14. Example 4 Find Measurements by Subtracting Find LM. Assume that the figure is not drawn to scale. Point M is between L and N. LM + MN= LNBetweenness of points LM + 2.6= 4Substitution LM + 2.6 – 2.6= 4 – 2.6Subtract 2.6 from each side. LM= 1.4Simplify.

15. Example 4 Find TU. Assume that the figure is not drawn to scale. T U V 3 in A. B. C. D. in.

16. Example 5 Write and Solve Equations to Find Measurements ALGEBRA Find the value of x and ST if T is between S and U, ST = 7x, SU = 45, and TU = 5x – 3. ST + TU= SUBetweenness of points 7x + 5x – 3= 45Substitute known values. 7x + 5x – 3 + 3= 45 + 3Add 3 to each side. 12x= 48Simplify. Draw a figure to represent this situation.

17. Example 5 Write and Solve Equations to Find Measurements x= 4Simplify. ST= 7xGiven = 7(4)x = 4 = 28Multiply. Answer: x = 4, ST = 28 Now find ST.

18. Example 5 ALGEBRA Find the value of n and WX if W is between X and Y, WX = 6n – 10, XY = 17, and WY = 3n. Draw a diagram first.

19. 5 minutes Individual Practice page 18 – 20 Do 21, 23, 25

20. Concept Equal vs. Congruent See p. 16 in the margin Lengths are equal and segments are congruent

21. Class Assignment – in notes (8 minutes) p. 18 - 21 9, 35, 42, 43 HW p. 18 – 21 10 – 16 even 22- 28, 33, 46, 48