# Measuring Segments - PC\|MAC Bell ringer 3x+5=20 4x+20 = 6x120 5x-60=7x+25 Measuring Segments

1.3 Ms. Verdino Objective Measure segments and determine accuracy of measurement Compute with measures Measuring

A line segment CAN be measured (unlike a line or ray) because it has 2 endpoints Precision: Depends on the SMALLEST unit available on the measuring tool. Measurement should be precise to within 0.5 unit of measure Tolerance: The margin of error (plus or minus .5 units) Precision

8.5 cm means that the ruler was divided into cm it could be 8.25 cm to 8.75 cm in actual length Measurement What does the measurement 5 inches mean? 1 inch increments of 1 = Tolerance: 5 = 4.5 in. 5 + = 5.5 in.

8 inches? inch increments, therefore ( ) of ( ) = in. Precise to inch add and subtract Between 8 to 8 inches Ruler Postulate Every point on a line can be paired with a real number

The real number that corresponds to a point is called the coordinate of the point. Distance The distance between points A and B is the absolute value of the difference of their coordinates. A

B Measuring Segment Lengths What is the length of AD? What is the length of BC?

Your turn! What is the length of GK? What is the length of HI? What is the length of JG? Segment Addition

Postulate If three points A, B, and C are collinear and B is between A and C, then AB + BC = AC A 10 cm part

B 4 cm + part = the whole 14 cm C

Segment Addition Postulate Find the value of x. PR = 120 PQ = 4x + 6 QR = 7x + 15 Find PQ and QR.

Segment Addition Postulate Find the value of y. GH = 7y + 3 HI = 3y 5 GI = 9y + 7 Find GH, HI, and GI.

Your turn! What are the lengths of GH and HI? GI = 32 GH = 3x +8 HI = 2x +4 Congruent segments: Two segments having the same measure.

If AB = CD, then AB CD B 5 cm A 5 cm C D

If AB CD, then AB = CD Comparing Segment Lengths Tell whether the segments are congruent. IJ and JK GH and IK HK and GJ

Your turn! Tell whether the segments are congruent. HJ and IK HJ and GI HK and GI The midpoint of a segment is a point that divides the

segment into two congruent segments. A point, line, ray, or other segment that intersects a segment at its midpoint is said to bisect the segment. That point, line, ray, or segment is called a segment bisector. Using the Midpoint Given: ST = 3x + 3 and TU = 2x + 9.

What is the value of ST? What is the value of TU? Your turn! Given: ST = x + 3 and TU = 4x 6. What is the value of ST? What is the value of TU?