Exploring Parallel Lines Using GSP

Open the GSP file that contains the following sketch.

In this activity, you will measure a lot of angles.  To help you know which angle you are measuring, you may want to label some (or all) of the points of the figure.

1.  Measure two pairs of alternate interior angles.  Record their measures on a sheet of paper.
    What do you notice?
    What can you conclude about the measures of alternate interior angles that are formed by parallel lines?

2.  Measure four pairs of corresponding angles.  Record their measures.
    What do you notice?
    What can you conclude about the measures of corresponding angles that are formed by parallel lines?

3.  Measure two pairs of alternate exterior angles.  Record their measures.
    What do you notice?
    What can you conclude about the measures of alternate exterior angles that are formed by parallel lines?

4.  Measure two pairs of consecutive interior angles.  Record their measures.
    What do you notice?
    What can you conclude about the measures of consecutive interior angles that are formed by parallel lines?