1.
Alternate Exterior Angles: the angles lie outside the two lines on opposite sides of the transversal
2.
Alternate Exterior Angles Theorem: if two parallel lines are cut by a transversal, then the pairs of alternate exterior angles are congruent (AEA congruency thrm) (<7 is congruent to <8)
3.
Alternate Interior Angles: The angles lie between the two lines on opposite sides of the transversal
4.
Alternate Interior Angles Theorem: if two parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruent (<3 is congruent to ,4) (AIA congruency theorem)
5.
Consecutive Interior Angles: angles that lie between two lines on the same side of the transversal
6.
Consecutive Interior Angles Theorem: if two parallel lines are cut by a transveral, then the pairs of consecutive interior angles are SUPPLEMENTARY (m<5+m<6=180 degrees) (CIA Thrm)
7.
Corresponding Angles: angles that occupy corresponding positions (above or below? right or left? same side?)
8.
Corresponding Angles Postulate: if two parallel lines are cut by a transversal, then the pairs of corresponding angles are congruent (<1 is congruent to <2) (Corr. <'s Post.)
9.
Flow Proof: a type of proof that uses arrows to show the flow of a logical argument. Statements are connected by arrows to show how each statement comes from the ones before it, and each reason is written below the statement it justifies.
10.
Parallel Lines: coplanar lines that do not intersect
11.
Parallel Planes: planes that do not intersect
12.
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.
13.
Perpendicular Lines Theorem: if two lines are perpendicular, then they intersect to form four right angles.
14.
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.
15.
Perpendicular Transversal Theorem: if a transversal is perpendicular to one of two parallel lines, then it is PERPENDICULAR to the other. (⊥ Trans. Thrm)
16.
Skew Lines: lines that are not coplanar and do not intersect
17.
Theorem (3.1): if two lines intersect to form a linear pair of congruent angles, then the lines are perpendicular.
18.
Theorem (3.2): If two sides of two adjacent acute angles are perpendicular, then the angles are complementary.
19.
Transversal: a line that intersects two or more coplanar lines at different points
