# Exploring the exterior angle theorem

- Author:
- Lea

## What are the relationships between interior angles and exterior angles?

Add an exterior angle that forms a straight line through AC. Label the end of this point D. Measure the angles of your shape. Using the arrow move point B.

What observations can you make about the measure of the angles as you move point B?

What is the relationship between the interior angles of a triangle and an exterior angle?