1. 3.1 Parallel & Perpendicular Lines September 21, 2012
3.1 Pairs of Lines and Angles
Parallel Lines: 2 lines that do not intersect and are coplanar.
k
k // m
m
Skew Lines: 2 lines that do not intersect and are NOT coplanar.
Parallel Planes: 2 planes that do not intersect.
Postulate 13: 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.
Postulate 14: 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.
Sep 29­7:21 AM
HW pg. 150 #3­13 odd, 19­31 odd 1

2. 3.1 Parallel & Perpendicular Lines September 21, 2012
Transversal: a line that intersects two or more lines at different points
Angles formed by transversals
Corresponding Angles: corresponding positions
2
6
Alternate Interior Angles: lie between the 2 lines and opposite sides of
transversal
4
5
Alternate Exterior Angles: lie outside the 2 lines on opposite sides of the
transversal 1
8
Consecutive Interior Angles: lie between the 2 lines on the same side
of the transversal
3
5
Sep 29­8:22 AM
HW pg. 150 #3­13 odd, 19­31 odd 2

3. 3.1 Parallel & Perpendicular Lines September 21, 2012
Sep 29­12:20 PM
HW pg. 150 #3­13 odd, 19­31 odd 3

4. 3.1 Parallel & Perpendicular Lines September 21, 2012
Sep 29­12:22 PM
HW pg. 150 #3­13 odd, 19­31 odd 4

5. 3.1 Parallel & Perpendicular Lines September 21, 2012
Sep 29­12:23 PM
HW pg. 150 #3­13 odd, 19­31 odd 5

6. 3.1 Parallel & Perpendicular Lines September 21, 2012
HW
pg. 150
#3­13 odd
19­31 odd
Sep 29­8:23 AM
HW pg. 150 #3­13 odd, 19­31 odd 6