Explore! Parallel Lines Intersected by a Transversal
line a || line b
Line c is a transversal. Drag the blue points on line c to move the transversal.
Note: Do not allow the blue points to fall inside the parallel lines or the angles will disappear!
Congruent Angles?
Which angle pairs are always congruent? Use some of the vocabulary that we learned in Lesson 3.1.
What else do you notice?
What do you notice about the relationship between the consecutive interior angle pairs? Use good vocabulary.
Does the same relationship exist among the consecutive exterior angles? Explain.