Term
Corresponding Angles (Postulate) 

Definition
If two parallel lines are cut by a transversal, then corresponding angles are congruent. 


Term
Alternate Interior Angles (Theorem) 

Definition
If two parallel lines are cut by a transversal, then alternate interior angles are congruent. 


Term
Sameside Interior Angles (Theorem) 

Definition
If two parallel lines are cut by a transversal, then sameside interior angles are supplementary. 


Term
Alternate Exterior Angles (Theorem) 

Definition
If two parallel lines are cut by a transversal, then alternate exterior angles are congruent. 


Term
Sameside Exterior Angles (Theorem) 

Definition
If two parallel lines are cut by a transversal, then sameside exterior angles are supplementary. 


Term
Definition of parallel lines 

Definition
coplanar lines that do not intersect 


Term
Name two kinds of lines that don't intersect 

Definition


Term

Definition
noncoplanar lines All noncoplanar lines are neither parallel nor intersecting. 


Term
Definition of parallel planes 

Definition
Planes that don't intersect. 


Term
If a line and a plane do not intersect, then ___ 

Definition


Term
Two parallel planes cut by a third plane (Theorem) 

Definition
If two parallel planes are cut by a third plane, then the lines of intersection are parallel. 


Term
Definition of a transversal 

Definition
a line that intersects two or more coplanar lines in different points 


Term
Definition of alternate interior angles 

Definition
Two nonadjacent interior angles on opposite sides of the transversal 


Term
Definition of sameside interior angles 

Definition
Two interior angles on the same side of the transversal. 


Term
Definition of corresponding angles 

Definition
Two angles in corresponding positions relative to the two lines 


Term
Definition of alternate exterior angles 

Definition
Two exterior angles on opposite sides of the transversal 


Term
Definition of sameside exterior angles 

Definition
Two exterior angles on the same side of the transversal 


Term
Abbreviation of "If two parallel lines are cut by a transversal, then corresponding angles are congruent." 

Definition
Parallel lines > Corresponding Angles are congruent. 


Term
Abbreviation of "If two parallel lines are cut by a transversal, then alternate interior angles are congruent." 

Definition
Parallel lines > alt. int. angles are congruent. 


Term
Transversal perpendicular to one of two lines (Theorem) 

Definition
If a transversal is perpendicular to one of two parallel lines, then it is perpendicular to the second line. 


Term
Abbreviation of "If two parallel lines are cut by a transversal, then sameside interior angles are supplementary." 

Definition
parallel lines > sameside interior angles are supp. 


Term
Abbreviation of "If two parallel lines are cut by a transversal, then alternate exterior angles are congruent. 

Definition
Parallel lines > alt. ext. angles are congruent 


Term
Abbreviation of "If two parallel lines are cut by a transversal, then sameside exterior angles are supplementary." 

Definition
Parallel lines > Sameside ext. angles are supp. 


Term
Corresponding angles (Proving lines are parallel; Theorem and Abbreviation) 

Definition
If two lines are cut by a transversal so that corresponding angles are congruent, then the lines are parallel.
Corresponding angles are congruent > parallel lines 


Term
Alternate interior angles (Proving lines are parallel; Theorem and Abbreviation) 

Definition
If two lines are cut by a transversal so that alternate interior angles are congruent, then the lines are parallel.
Alt. int. angles are congruent > parallel lines 


Term
Sameside interior angles (Proving lines are parallel; Theorem and Abbreviation) 

Definition
if two lines are cut by a transversal so that sameside interior angles are supplementary, then the lines are parallel.
Sameside int. angles are supp. > parallel lines 


Term
Alternate exterior angles (Proving lines are parallel; Theorem and Abbreviation) 

Definition
If two lines are cut by a transversal so that alternate exterior angles are congruent, then the lines are parallel.
Alt. ext. angles are congruent > parallel lines 


Term
Sameside exterior angles (Proving lines are parallel; Theorem and Abbreviation) 

Definition
If two lines are cut by a transversal so that sameside exterior angles are supplementary, then the lines are parallel.
Sameside angles are congruent > Parallel lines



Term
Perpendicular line (Property of Parallel Lines) 

Definition
If a transversal is perpendicular to one of two parallel lines, then it is perpendicular to the second line also. 


Term
Perpendicular Lines Theorem (Proving Lines are Parallel) 

Definition
In a plane, two lines perpendicular to the same line are parallel 


Term
"Exactly 1 Line perpendicular to a given line" Theorem 

Definition
Through a point outside a line, there is exactly one line perpendicular to the given line 


Term
"Exactly one line parallel to the given line" Theorem 

Definition
Through a point outside a line, there is exactly one line parallel to the given line. 


Term

Definition

