# What are alternate interior angles?

##### 1 Answer

Feb 5, 2016

Two parallel lines and one transversal intersecting it form

Two pairs of these angles are called *alternate interior*.

See picture below.

#### Explanation:

A pair of angles *alternate interior*.

So is a pair of angles

They are called *alternate* because

They are called *interior* because both

Two angles forming an *alternate interior* pair are always congruent to each other, they have exactly the same measure.