1 / 11

Line Segments

Line Segments. Information. Line segments. A line segment is part of a line that contains all points between and including two endpoints. B. A. The points A and B are the endpoints of the line segment. The line segment is named AB or BA.

michelina
Télécharger la présentation

Line Segments

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Line Segments

  2. Information

  3. Line segments A line segment is part of a line that contains all points between and including two endpoints. B A The points A and B are the endpoints of the line segment. The line segment is named AB or BA. How many points are there in a line segment? There are infinitely many points in a line segment. This means that no matter how close A and B are, there is always another point between them.

  4. Distance and length of segments Line segments have a length, which is the distance between the two endpoints. The length of AB is denoted AB. Distance can be measured using a ruler. On a coordinate axis, the distance between two points is the difference between coordinates of the endpoints. B A –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 6

  5. Congruence Segments are called congruent if they have the same length, e.g. AB = CD. Congruent segments are denoted using the symbol ≅, e.g., AB ≅CD. D E A B C –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 6 Properties of congruence AB ≅AB reflexive: if AB ≅BC, thenBC ≅AB symmetric: if AB ≅BC and BC ≅CD, thenAB ≅CD transitive:

  6. Equipment needed for constructions Which equipment do you need for constructing line segments? ruler protractor sharp pencil compass

  7. Constructing a line segment

  8. Segment addition postulate and midpoint The segment addition postulate: if B is between A and C then: AB + BC=AC A B C The midpoint, M, of a line segment is the point that bisects, or equally divides, a line segment into two congruent line segments: AM≅ MC, which means AM = MC. A M C In figures, congruent segments are denoted with tick marks.

  9. Congruent segments

  10. Segment addition postulate Ashley and Corinne live 21 blocks apart on the same street. Brian lives between them and 7 blocks away from Ashley. How far apart do Brian and Corinne live? 1. Represent the street as a line, with points representing where the children live: A B C 2. Translate the information given into line segment lengths: AC=21 AB=7 3. Substitute the values into the segment addition postulate to find the answer: AB + BC = AC segment addition postulate: 7 + BC = 21 substitute: BC = 21 – 7 =14 rearrange and solve:

  11. Summary activity

More Related