# Exploring Angle Relationships with Triangles

Topic:
Triangles

## Directions

For each of the following applets, explore the given angle relationships in order to make generalizations about the relationships between the angles.

## Part I: Angle Sum in a Triangle

What do you notice about the measures of the angles in triangle ABC? Move points A, B, and C to create different triangles.  What do you notice about the angles in the new triangle?  Will this always be true?

## Part II: Exterior Angles 1

Angles BAD, CBE, and ACF are exterior angles of triangle ABC.  What do you notice about the exterior angles of this triangle? Move points A, B, and C to create different triangles.  What do you notice about the exterior angles in the new triangles?  Will this always be true?

## Part III: Exterior Angles 2

Angles CAH, ABI, and BCJ are also exterior angles of triangle ABC.  What do you notice about the angles of this triangle? Move points A, B, and C to create different triangles.  What do you notice about the exterior angles in the new triangles?  Will this always be true?