Créer une présentation
Télécharger la présentation

Télécharger la présentation
## 1-3 Measuring Segments

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**1-3 Measuring Segments**Chapter 1 The Tools of Geometry**Last class we worked on new vocabulary and 3 postulates**• You may use • Your notes from class • Your Lesson Closure Book …to complete the assignment 1-2 Practice. • We will check this assignment in 30 minutes and turn it in.**Today’s Lesson: Measuring Segments**The Burbot fish are found in Europe, Asia, and North America (the Great Lakes). Adult Burbots grow to be between 30 and 60 cm. This shows a young fish. How would you determine its length to the nearest centimeter? Use this scale**Postulate 1-5 Ruler Postulate**• The real number that corresponds to a point on a number line is the coordinate of the point.**Find the measure of each segment.**• What is DF? Use the Ruler Postulate • What is AD? • What is BD? • What is BF?**Postulate 1-6 Segment Addition Postulate**• If three points, A, P, and B are collinear and P is between A and B, then AP + PB = AB.**3x + 8**2x + 4 L M N • If LN = 32, what are LM and MN?**4x + 6**7x + 15 J K L You try this one • If JL = 120, what are JK and KL?**Comparing Segment Lengths**• When numerical expressions have the same value, we say they are equal. 3 + 7 = 4 + 6 • If two segments have the same length, we say they are congruent segments. Symbol: ≅**Comparing Segment Lengths**Are AC and DF congruent? Are AC and CD congruent?**Comparing Segment Lengths**Point C is equidistant from both A and D. Therefore it is the midpoint of AD. Midpoint: a point that divides a segment into two congruent segments.**Any point, line, or ray that intersects a segment at its**midpoint is said to bisect the segment. • That point, line, ray, or segment is called a segment bisector.**We can use the midpoint to find solutions to problems.**T S R • S is the midpoint of RT. • What are RS and ST? • What is RT? 7x – 3 3x + 1