1. Geometry Lesson 1 – 2 Linear Measure Objective: Measure segments. Calculate with measures.

2. Line segment Can you measure a line? Line segment (or just segment) Can be measured because it is a part of a line Has 2 endpoints.

3. Reading math Read the following: read as ‘ segment AB ’ read as ‘ the measure of segment AB ’

4. Find the Length Find AB About 4 cm About 3.7 cm About 2 cm

5. Find the length About 1 ¼ in. Measured in 1/16 of an inch.

6. Betweenness of points Point M is between points P and Q if and only if P, Q, and M are collinear and PM + MQ = PQ The parts add up to be the whole.

7. Example Find EG. Assume that the figure is not drawn to scale. Write out a general statement. EF + FG = EG

8. Example Find JL. JK + KL = JL 8.4 + 3.9 = JL 12.3 = JL JL = 12.3 cm

9. Example Find AB. AB + BC = AC AB + 5.8 = 13.2 AB = 7.4 m

10. Example Find QR. PQ + QR = PR

11. Example Find the value of a and XY if Y is between X and Z, XY = 3a, XZ = 5a – 4 and YZ = 14. Draw a picture XY + YZ = XZ 3a + 14 = 5a - 4 14 = 2a - 4 18 = 2a 9 = a XY = 3a = 3(9) = 27

12. Example Find x and BC if B is between A and C, AC = 4x – 12, AB = x, and BC = 2x + 3 AB + BC = AC x + 2x + 3 = 4x - 12 3x + 3 = 4x - 12 3 = x - 12 15 = x BC = 2x + 3 = 2(15) + 3 = 33

13. Congruent Segments Congruent segments Segments that have the same measure Symbols: read “ is congruent to ” red tick marks on congruent sides

14. Equal vs. Congruent Lengths are equal Segments are congruent Correct: Incorrect:

15. Example Name the congruent segments.

16. Constructions Drawings of geometric figures using measuring tools such as a ruler and protractor.

17. Homework Pg. 18 1 – 9 all, 10 – 30 EOE, 40, 46 – 60 E