Transcript 2.2
3.1 LINES AND ANGLES GOAL 1 RELATIONSHIPS BETWEEN LINES Vocabulary •parallel lines—Be sure you understand the notation! •skew lines •parallel planes EXAMPLE 1 Extra Example 1 Think of each segment in the diagram as part of a line. Which of the lines appear to fit the description? V a. parallel to TW and contains V UV b. perpendicular toTW and contains V c. skew to TW and contains V WV RV or SV d. Name the plane(s) that contain V and appear to be parallel to plane TPQ. plane VRS PARALLEL AND PERPENDICULAR POSULATES Parallel Postulate If there is a line and a point not on the line, then there is exactly one line through the point parallel to the given line. Perpendicular Postulate If there is a line and a point not on the line, then there is exactly one line through the point perpendicular to the given line. Construction A Perpendicular to a Line Work through the construction activity on page 130. Checkpoint Think of each segment in the diagram as part of a line. Which of the lines appear to fit the description? 1. parallel to JN and contains H HM 2. perpendicular to JN and contains H 3. skew to JN and contains H JH GH, KH 4. Name the plane(s) that contain H and appear to be parallel to plane LMN. plane GHJ 3.1 LINES AND ANGLES GOAL 2 IDENTIFYING ANGLES FORMED BY TRANSVERSALS Vocabulary •transversal •corresponding angles EXAMPLE 2 •alternate exterior angles •alternate interior angles •consecutive interior angles (same side interior angles) Extra Example 2 List all pairs of angles that fit the description. a. corresponding 1 and 3; 2 and 4; 5 and 7; 6 and 8 b. alternate exterior 1 and 8; 5 and 4 c. alternate interior 2 and 7; 3 and 6 d. consecutive interior 2 and 3; 6 and 7 EXAMPLE 3 Checkpoint List all pairs of angles that fit the description. 1. corresponding 1 and 3, 2 and 4, 5 and 7, 6 and 8 2. alternate exterior 1 and 8, 4 and 5 3. alternate interior 2 and 7, 3 and 6 4. consecutive interior 6 and 7, 2 and 3 1 2 5 6 3 4 7 8 QUESTIONS? homework • Pg 132 #1-26