Similar to top half of p. 128 - Copy that OR  Copy the gold boxes and the angle relationships below.

Definition of parallel lines two lines are parallel if and only if they lie in the same plane and do not intersect
Definition Of skew lines two lines are skew if and only if the lines do not intersect AND are not in the same plane.
Definition of transversal A line that intersects two or more lines in a plane at different points.


Note that the two lines do not look parallel.  If they are not parallel, then angles 1 to 4 have no special relationship with angles 5 to 8.  HOWEVER, if these lines are parallel then much can be told about all the angles.