### Alternate Interior Angles

Inside angles of two lines intersected by a transversal and on opposite sides of the transversal (angles 3,6 and 4,5)

### Alternate Exterior Angles

Outside angles of two lines intersected by a transversal and on opposite sides of the transversal (angles 2,7 and 1,8)

### Consecutive Interior Angles

Inside angles of two lines intersected by a transversal and on the same side of the transversal (angles 4,6 and 3,5)

### Corresponding Angles

Pair of angles formed by two lines and a transversal consisting of an interior angle and an exterior angle that have different vertices and that lie on the same side of the transversal (angles 2,6 and 1,5 and 4,8 and 3,7)

### Corresponding Angles Postulate

Two parallel lines cut by a transversal create corresponding angles that are congruent.

### Alternate Interior Angles Theorem

Two parallel linescut by a transversal create pairs of alternate interior angles that are congruent.

### Consecutive Interior Angles Theorem

Two parallel lines cut by a transversal create pairs of consecutive interior angles that are supplementary.

### Alternate Exterior Angles Theorem

Two parallel lines cut by a transversal create pairs alternate exterior angles that are congruent.

### Perpendicular Transversal Theorem

If a transversal is perpendicular to one of the two parallel lines, then it is perpendicular to the other

### Corresponding Angles Converse Postulate

Equal, two lines are cut by a transversal so that corresponding angles are congruent then the lines are parallel

### Alternate Interior Angles Converse

Negative Reciprocals, If two lines are cut by a transversal so that alternate interior angles are congruent, then the lines are parallel

### Consecutive Interior Angles Converse

If two lines are cut by a transversal so that consecutive interior angles are supplementary, then the lines are parallel

### Alternate Exterior Angles Converse

if two lines are cut by a transversal so that the alternate exterior angles are congruent, then the lines are parallel

### Flow Proof

like a two column proof but the statements are connected by arrows to show how each statement comes from the ones before it

### 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 given line.

### coincident lines

when the graphs of two lines are the same or coincidentally on top of one another