Warm Up Problem of the Day Lesson Presentation

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 contains two of the points? Name the lines. 3; AB, AC, BC

Give the complement and supplement of each angle. Warm Up Give the complement and supplement of each angle. 1. 80° 2. 64° 3. 15° Compliment Supplement 10°, 100° 26°, 116° 75°, 165°

Insert Lesson Title Here More Warm-Up Give the complement of each angle. 1. 75° 2. 45° Give the supplement of each angle. 3. 130° 4. 15° 5. Identify the type of angle pair shown. 15° 45° 50° 165° adjacent

Learn to classify the different types of lines.

Insert Lesson Title Here WRITE THESE DOWN: parallel lines perpendicular lines skew lines

Y W Z X Intersecting lines are lines that cross at one common point. Line YZ intersects line WX. YZ intersects WX. B A M L Parallel lines are lines in the same plane that never intersect. Line AB is parallel to line ML. AB ML.

Long “Lines”?

S R T U Perpendicular lines intersect to form 90° angles, or right angles. Line RS is perpendicular to line TU. RS TU. Writing Math The square inside a right angle shows that the rays of the angle are perpendicular.

American Red Cross

Skew lines are lines that lie in different planes 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

A Skew s me!

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

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

Look, There’s Worm!

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

Parallel Lines? Legs? Sides?

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

Try This: Example 1A Classify each pair of lines. A. The lines are in the same plane. They do not appear to intersect. They are parallel.

Try This: Example 1B Classify each pair of lines. B. The lines intersect to form right angles. They are perpendicular.

LOOK!!

Try This: Additional Example 1C Classify each pair of lines. C. The lines are in different planes and are not parallel or intersecting. They are skew.

Try This: Additional Example 1D Classify each pair of lines. D. The lines cross at one common point. They are intersecting.

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.

See, they may look like they intersect, but they are on different planes!

See, they may look like they intersect, but they are on different planes!

See, they may look like they intersect, but they are on different planes!

Try This: 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.

Insert Lesson Title Here 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