CHAPTER 3 Parallel and Perpendicular Lines 3 1
- Slides: 13
CHAPTER 3 Parallel and Perpendicular Lines
3. 1 IDENTIFY PAIRS OF LINES AND ANGLES
Vocabulary Types of Lines Definition / Characteristics Symbol Parallel lines • never intersect • are on the same plane • have the same slope Perpendicular Lines • cross to form 90 angles • are on the same plane ┴ Skew lines • never intersect • do not lie on the same plane n/a
EXAMPLE 1 Think of each segment in the figure as part of a line. Which line(s) or plane(s) in the figure appear to fit the description? 1) 2) 3) 4) Line(s) parallel to line CD and containing point A Line BA Line(s) skew to line CD and containing point A Line AH Line(s) perpendicular to line CD and containing point A Line DA Plane(s) parallel to plane EFG and containing point A Plane DCB
Postulates l A postulate is a true statement, which does not require to be proved.
Parallel Postulate There is exactly 1 line through a point parallel to another line. l.
Perpendicular Postulate There is exactly 1 line through a point perpendicular to another line. l .
EXAMPLE 2 Identifying Parallel and Perpendicular Lines The given line markings show the roads are related to one another. 1. Name a pair of parallel lines. 2. Name a pair of perpendicular lines. 3. Is line FE parallel to line AC ? Explain.
Angle Pairs - review (formed by the intersection of 2 lines) Description/ Properties Vertical Angles angles that are opposite one another l • These ’s are = Linear pair angles that are both adjacent and supplementary (next to) ( __ +___ = 180 ) l Picture Name 2 pairs of vertical angles in the picture above: 1 & 4 2 & 3 Name 4 sets of linear pairs in the picture above: 1 & 2 2 & 4 3 & 1
Transversal a line that crosses 2 other lines
1 2 5 6 3 4 7 8 Angle Pairs (formed by a transversal) Angles are…. Corresponding Angles Alternate Interior Angles Alternate Exterior Angles Consecutive Interior Angles are on the ______ side of the transversal in the same position of each intersection same inside of the 2 lines opposite outside of the 2 lines opposite inside the 2 lines and form a linear pair same Picture
Extra Practice Example 3 Identify all pairs of angles of the given type: A. Corresponding E. Vertical Angles 1 & 5 2 & 6 3 & 7 4 & 8 1 & 4 2 & 3 A & E B & F D & H C & G 5 & 8 6 & 7 B. Alternate interior 4 & 5 2 & 7 D & E B & G C. Alternate exterior F. Linear Pairs 1 & 8 3 & 6 1 & 2 2 & 4 3 & 4 A & H C & F 3 & 1 5 & 6 5 & 7 D. Consecutive interior 7 & 8 8 & 6 2 & 5 4 & 7 B & E D & G
GUIDED PRACTICE Classify the pair of numbered angles in each picture Alternate Exterior angles Corresponding angles Alternate Interior angles
- Chapter 3 review parallel and perpendicular lines
- Chapter 3 parallel and perpendicular lines
- Chapter 3 parallel and perpendicular lines
- Unit 3 parallel and perpendicular lines
- Unit 3 test: parallel and perpendicular lines
- Proofs involving parallel and perpendicular lines
- Two parallel lines have the same slope
- Parallel perpendicular or neither
- Parallel and perpendicular lines slope intercept form
- Slopes of parallel and perpendicular lines assignment
- Lesson 8 parallel and perpendicular lines
- Algebra 1 parallel and perpendicular lines
- If line a contains q(5 1)
- Parallel vs perpendicular lines