1. 1.2 Linear Measure and Precision Honors Geometry Reitz High School 2015 - 2016

2. Objectives Measure segments and determine accuracy of measurements. Compute with measures. Textbook Pages 14 - 24

3. Important Terms Line segment: a portion of a line delimited by two end points. A line segment can be measured, because it has two endpoints. Precision: the degree to which the correctness of a quantity is expressed. The measurement should be precise within 0.5 units of measure. Ex: if cm is smallest unit, can come w/in ±.5 cm for precision Ex: if mm is smallest unit, can come w/in ±.5 mm

4. Examples Find the precision for the measurement: 1. 5 mm2. 8 ½ inches

5. Important Terms Between: A Point M is between points P and Q if and only if P,Q, and M are collinear and PM + MQ = PQ. (Point M DOES NOT have to be a midpoint)! Congruent: When segments have the same measure, they are said to be congruent.

6. Examples 2 2 A B C Find AC: R P Q 2y 21 Find RQ:

7. A B C D E F

8. How is Congruence different than Equality? Congruence Same shape- similar geometric shapes Same measurement equal in number Equality Same measurement – equal in number

9. Example: Equal but not Congruent

10. Assignment Workbook p. 4, #’s 1 – 11 Textbook p. 18 – 19, #’s 11 – 31 odds.