3-2: Angles and Parallel Lines

3-2: Angles and Parallel Lines

Corresponding Angles Postulate

If two parallel lines are cut by a transversal, then each pair of corresponding angles are congruent.

Alternate Interior Angles Theorem

If two parallel lines are cut by a transversal, then each pair of alternate interior angles is congruent.

Consecutive Interior Angles Theorem

If two parallel lines are cut by a transversal, then each pair of consecutive interior angles is supplementary.

Alternate Exterior Angles Theorem

If two parallel lines are cut by a transversal, then each pair of exterior angles is congruent.

If 

 $m\angle4\ =\ 2x-17$  and  $m\angle1\ =\ 85,$  find  $x.$  

Find   $y$  if 

 $m\angle3\ =\ 4y+30$  and  $m\angle7\ =\ 7y+6.$