3-1 Parallel and Perpendicular Lines 3-1 Parallel Lines and Transversals

Identify the relationships between two lines and planes.

Parallel lines – Two or more lines that are coplanar and do not intersect. Parallel planes – Two or more planes that do not intersect.

Skew – Two lines that do not intersect and are not coplanar.

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 give line.

Identifying Angles formed by Transversals Transversal – A line that intersects two or more coplanar lines at different points. Interior angles <1, <2, <3, <4 Exterior angles <5, <6, <7, <8 t

Corresponding Angles Angles on the same side of the transversal. One angle is an interior angle and the other is an exterior angle They are not adjacent <1 and <5 <2 and <6 <3 and <7 <4 and <

Alternate Interior Angles Two interior angles that lie between the two lines on opposite sides of the transversal. <4 and <5 <3 and <

Alternate Exterior Angles Two exterior angles that lie outside the two lines on opposite sides of the transversal. <1 and <8 <2 and <

Consecutive Interior Angles Two angles that lie between the two lines on the same side of the transversal. <3 and <5 <4 and <

Consecutive interior angles are sometimes called same side interior angles.

Name all planes parallel to plane ABC. Name all segments that intersect AB Name all segments that are parallel to HB. Name all segments that are skew to FH. Name all segments Perpendicular to FC.

Vertical angles Supplementary angles Exterior angles Interior angles Consecutive interior angles Alternate interior angles Alternate exterior angles Corresponding angles t m l

Assignments Class work page 175 problems 1-20 Homework page 176 problems 21-36