3.1 Vocab (And 3.3 Converse)

Parallel Lines

Coplanar lines that dont intersect

Skew Lines

Noncoplanar lines

Parallel Planes

Planes that dont intersect

A line and plane are parallel if and only if…

They do not intersect

Transversal

Line that intersect 2 or more coplanar lines at different points

Corresponding Angles

2 angles in corresponding positions relative to the 2 lines and transversal

Alternatie Interior Angles

2 nonadjacent interior angles on opposite sides of the transversal

Alternate Exterior Angles

2 nonadjacent exterior angles on opposite sides of the transversal

Same Side Interior Angles

2 interior angles on the same side of the transversal

Same side exterior Angles

2 exterior angles on the same side of the transversal

Corresponding Angle Postulate;

Alternate Interior Angle Theorem;

Alternate Exterior Angles Theorem;

Same Side Interior Angle Theorem;

Same Side Exterior Angle Theorem;

Perpendicular Transversal Theorem

If 2 parallel lines are cut by a transversal, then…..

• Corresponding angles are congruent

• alternate exterior angles are congruent

• same side interior angles are supplementary….. etc

Converse of:

Corresponding angle postulate

Alternate interior angle theorem

If 2 lines rae cut by a transversal, and corresponding angles are congruent, then the lines are parallel

If 2 lines are cut by a transversal, and alternate interior angles are congruent, then the lines are parallel

Etc… (if 2 lines are cut by a transversal, and________________, then the lines are parallel

Perpendicualar Transversal Theorem Def and Converse

Def: If a transversal is perpendicular to one of 2 parallel lines then it is parallel to the other one also

Converse: In a plane, 2 lines perpendicular to the same lines are parallel