# Angles

## A.1 Supplementary and Vertical Angles

**Big Idea**

Understand why vertical angles are congruent using properties of supplementary angles.

## A.2 Corresponding Angles

**Big Idea**

Discover that corresponding angles are congruent.

## A.3 Alternate Interior and Same Side Interior Angles

**Big Idea**

Discover the relationship between same-side interior and alternate interior angles when two parallel lines are cut by a transversal.

## A.4 Missing Angles

**Big Idea**

Use angle relationships to find missing angles when two parallel lines are cut by a transversal.

## A.5 Angle Sum Theorem

**Big Idea**

Explain why the sum of the measures of the interior angles of a triangle is 180 degrees.

## A.6 Exterior Angle Theorem

**Big Idea**

Apply the exterior angle theorem to find missing angles of a triangle.