3.1 and 3.2 Parallel lines and transversals Chapter 3 3.1 and 3.2 Parallel lines and transversals
Parallel Lines Parallel lines are coplanar lines that do not intersect. symbol ||
Skew Lines Skew lines are lines that are non-coplanar and do not intersect. Ex: What lines are skew to ?
Parallel Planes Parallel planes are planes that do not intersect. Ex : Name a set of parallel planes.
Example 1 – do not need to copy problem for notes
Transversal Transversal - A line that intersects two or more lines in a plane at different points. t m n
When the transversal intersects two lines, eight angles are formed, which have special names.
Alternate Interior Angles- Nonadjacent interior angles that lie on opposite sides of the transversal.
Alternate Exterior Angles- nonadjacent exterior angles that lie on opposite sides of the transversal. Angles 1 and 7 Angles 2 and 8
Corresponding Angles – lie on the same side of the transversal and in corresponding positions.
Same Side Interior Angles – interior angles that lie on the same side of the transversal.
Take out worksheet pages 59, 63, 67, 87 #1-12, 14,16-24, 27
Additional Problems
3-1 Corresponding angles postulate If two parallel lines are cut by a transversal, then corresponding angles are congruent. 2 6, 1 5, 3 7, 4 8 1 2 3 4 5 6 7 8 Lesson 2-4: Angles and Parallel Lines
3-2 Same Side Interior Angles Theorem (or Consecutive angles theorem) If two parallel lines are cut by a transversal, then then each pair of same side interior angles is supplementary. m3 +m5 = 180º, m4 +m6 = 180º 1 2 3 4 5 6 7 8 Lesson 2-4: Angles and Parallel Lines
Lesson 2-4: Angles and Parallel Lines Alternate Angles 3-1 Alternate Interior Angles Thereom: If two parallel lines are cut by a transversal, then each pair of alternate interior angles are Congruent. 3-3 Alternate Exterior Angles: If two parallel lines are cut by a transversal, then each pair of alternate exterior angles are Congruent. 3 6, 4 5 2 7, 1 8 1 2 3 4 5 6 7 8 Lesson 2-4: Angles and Parallel Lines
Worksheet 3-2 1-12, 14, 15, 16
Homework Pg 144-145 11-29, 37-42 Pg 153-154 7-9, 12-20, 22, 23-24