DO NOW:•1. Write as a biconditional: If it is an egg

then it is green. •2.

3.1 Pairs of Lines and AnglesOBJ: The student will be able to identify lines, planes, parallel liens, perpendicular, and pairs of angles formed by transversal.

Definitions•Parallel Lines: two lines that do not

intersect and are coplanar.•Skew Lines: two lines that do not

intersect and are not coplanar.•Parallel Planes: two planes that do not

intersect

Ex. 1

Postulate 3.1 •Parallel Postulate: If there is a line and

a point not on the line, then there exists exactly one line through the point parallel to the given line.

•There is exactly one line through P parallel to l.

Postulate 3.2•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.

•There is exactly one line through P perpendicular to l.

Ex. 2

Transversals•Transversal: a line that intersects two or

more coplanar lines at different points•There are 4 types of angles formed by

transversals: corresponding, alternate interior, alternate exterior, and consecutive interior angles.

•Corresponding Angles: two angles that have corresponding positions.

•Alternate Interior Angles: two angles that lie between the two lines on opposite sides of the transversal.

•Alternate Exterior Angles: two angles that lie outside the two lines and on opposite sides of the transversal.

•Consecutive Interior Angles: two angles that lie between the two lines and on the same side of the transversal.

Ex. 3

HW:•Pg.129 3-18, 24 a-c