| A | B |
|---|
| Skew lines | lines that do not lie in the same plane |
| Parallel lines | coplaner lines which never intersect |
| Transversal | a line which intersects two or more lines |
| Alt. int. angles | angles which lie on opposite sides of a trans. and on the int. of the other two lines |
| Alt. ext. angles | angles whicj lie on opposite sides of trans. and on the twol ines |
| Corresponding angles | angles on the same side of the trans. with one angle on int. and one on ext. |
| Consecutive int. angles | angles on the same side of the trans. and on the int. of the two lines |
| Thm 1 | II => alt. ext. angles are congruent |
| Thm 2 | II => corres. angles are congruent |
| Thm 3 | II => cons. int. angles are supp. |
| Thm 4 | II => trans. perpendicular first line, perpendicular second line |
