# Lesson 3.2 - Properties of Parallel Lines

- Author:
- Cristin Young, GeoGebra Materials Team

Lines AB and FC are parallel.

Use points A, B, and C to change the angle values.
Make as many observations as you can.

What are two observations you made when you moved points A, B, and C?

Lines AB and FC are parallel. What do we call line EG?

## Lesson 3.1 Review - Angle Pairs Formed by Transversals

Look at the applet below. Explore the different types of angles formed by a transversal.
Click each angle type to see them highlighted.
Drag the two slider bars to change the location/direction of the parallel lines and transversal.

## Use the figure below to answer the following questions.

If a transversal intersects two parallel lines, what do you know about corresponding angles? You may use the figures above to help.

If a transversal intersects two parallel lines, what do you know about alternate interior angles? You may use the figures above to help.

If a transversal intersects two parallel lines, what do you know about same-side interior angles? You may use the figures above to help.

If a transversal intersects two parallel lines, what do you know about alternate exterior angles? You may use the figures above to help.