# Exterior angle on parallel lines and a Transversal

- Author:
- HIlary

Parallel lines are lines in a plane which never meet or intersect. The lines have the same slope.
A transversal is a line that intersects at least two other lines.
In this activity you will be able to observe and analyze the eight angles created when a transversal cuts two parallel lines.
Move the transversal by selecting and dragging point C and/or point H.
Analyze the eight angles created when a transversal cuts two parallel lines.

What angle is congruent to the exterior angle of the triangle's angle ABC??
How do you know?
How is the measure of <ABC related to the measure of the exterior angle.
What is the sum of the measure of the triangles other interior angles?
HOw is the sum related to the measure of the exterior angle?
Move the transversal and see if the relationship remains true?
Hints:
What are the angle measurements of < CBA and < FBD?
<CBA = __________ < FBD = ___________
What are <CBA and <FBD called?:
___________________
Do you see any other angle pairs with the same relationship?
What other angle pairs do you see?
Give an example of
1.) Vertical Angles
2.) Corresponding Angles
3.) Supplementary Angles
4.) Alternate Interior Angles
5.) Alternate Exterior