1. Course 1 8-4 Classifying Lines 8-4 Classifying Lines Course 1 Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day

2. Course 1 8-4 Classifying Lines Warm Up Give the complement of each angle. 1. 80° 2. 64° 3. 15° 4. 48 ° 10° 26° 75° 42°

3. Course 1 8-4 Classifying Lines Problem of the Day Draw three points that are not in a straight line. Label them A, B, and C. How many different lines can you draw that contain two of the points? Name the lines. 3; AB, AC, BC

4. Course 1 8-4 Classifying Lines Learn to classify different types of lines

5. Course 1 8-4 Classifying Lines Vocabulary parallel lines perpendicular lines skew lines

6. Course 1 8-4 Classifying Lines Intersecting lines are lines that cross at one common point. Parallel lines are lines in the same plane that never intersect. Line YZ intersects line WX. YZ intersects WX. Line AB is parallel to line ML. AB ML. Y W Z X B A M L The red arrows on the lines show that the lines are parallel. Reading Math

7. Course 1 8-4 Classifying Lines

8. Course 1 8-4 Classifying Lines Perpendicular lines intersect to form 90° angles, or right angles. Line RS is perpendicular to line TU. RS TU. S R TU Skew lines are lines that lie in different planes. They are neither parallel nor intersecting. Line AB and line ML are skew. AB and ML are skew. M L A B

9. Course 1 8-4 Classifying Lines

10. Course 1 8-4 Classifying Lines

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12. Course 1 8-4 Classifying Lines Additional Example 1A: Classifying Pairs of Lines Classify each pair of lines. The lines intersect to form right angles. They are perpendicular.

13. Course 1 8-4 Classifying Lines Additional Example 1B: Classifying Pairs of Lines Classify each pair of lines. The lines are in different planes and are not parallel or intersecting. They are skew.

14. Course 1 8-4 Classifying Lines Additional Example 1C: Classifying Pairs of Lines Classify each pair of lines. The lines are in the same plane. They do not appear to intersect. They are parallel.

15. Course 1 8-4 Classifying Lines Additional Example 1D: Classifying Pairs of Lines Classify each pair of lines. The lines cross at one common point. They are intersecting.

16. Course 1 8-4 Classifying Lines Check It Out: Example 1A Classify each pair of lines. The lines are in the same plane. They do not appear to intersect. They are parallel.

17. Course 1 8-4 Classifying Lines Check It Out: Example 1B Classify each pair of lines. The lines intersect to form right angles. They are perpendicular.

18. Course 1 8-4 Classifying Lines Check It Out: Example 1C Classify each pair of lines. The lines are in different planes and are not parallel or intersecting. They are skew.

19. Course 1 8-4 Classifying Lines Check It Out: Example 1D Classify each pair of lines. The lines cross at one common point. They are intersecting.

20. Course 1 8-4 Classifying Lines Additional Example 2: Application The handrails on an escalator are in the same plane. What type of line relationship do they represent? The handrails are in the same plane and do not intersect. The lines are parallel.

21. Course 1 8-4 Classifying Lines Check It Out: Example 2 The roads are in the same plane. What type of line relationship do they represent? The lines cross at one common point. The lines are intersecting.

22. Course 1 8-4 Classifying Lines Draw an example of each type of line. Parallel lines Intersecting lines Perpendicular lines Skew lines

23. Course 1 8-4 Classifying Lines Do you have any questions concerning the types of lines that we discussed in class today? HELP!

24. Course 1 8-4 Classifying Lines Lesson Quiz 1. Sketch a pair of perpendicular lines. 2. Sketch a pair of parallel lines. Use the figure to classify the lines. 3. AD and BC 4. AD and CF 5. AB and BG parallel skew perpendicular

25. Course 1 8-4 Classifying Lines Learned to classify different types of lines.

26. Course 1 8-4 Classifying Lines Numbers 1 - 15 on pages 430 - 431