# Alternate Exterior Angles in Parallel Lines

How to solve alternate exterior angles in parallel lines problems: definition, theorem, example, and its solution.

## Definition

By two lines and a transversal,

2 pairs of alternate exterior angles are formed.

(same colored angles)

## Theorem

If a transversal passes through parallel lines,

then a pair of alternate exterior angles is congruent.

(= Same colored angles are congruent.)

## Example

These two horizontal lines are parallel.

So the given alternate exterior angles are congruent.

So 8*x* + 10 = 74.