Chapter 3 – Parallel and Perpendicular Lines

Section 3.1 – Identify Pairs of Lines and Angles

HW #13 pg. 150#7-10, 18-23, 34, 35, 37

Definitions

Parallel Lines Lines that do not intersect

Skew Lines Lines that do not intersect and are not

coplanar Parallel Planes

Planes that do not intersect

Postulates

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 that

line, then there is exactly one line through that point that is perpendicular to that line.

Definitions Transversal

A line that intersects two or more coplanar lines at different points

Corresponding Angles Angles with the same position

Alternate Interior Angles Angles between the two lines and on opposite sides of

the transversal Alternate Exterior Angles

Angles outside the two lines and on opposite sides of the transversal

Consecutive Angles Angles in between the two lines and on the same side

as the transversal

Example

Name the angle pairs