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# Vertical angles review

Review the basics of vertical angles, and try some practice problems.

## Vertical angles

Vertical angles are angles opposite each other where two lines cross.
For example, angle, A, X, D and angle, B, X, C are vertical angles in the following diagram:

### Practice set

Problem 1A
Are angle, A, P, D and angle, C, P, B vertical angles?
All segments that appear straight are straight.

Want to try more problems like this? Check out this exercise.

## Use vertical angles to find a missing angle measure

Let's look at an example.
What is the measure of angle x?
First, let's find the measure of the pink angle:
The pink and blue angles add up to 180, degrees because they are adjacent and form a straight line.
start color #ff00af, start text, p, i, n, k, space, a, n, g, l, e, end text, end color #ff00af, equals, 180, degrees, minus, start color #6495ed, 121, degrees, end color #6495ed, equals, start color #ff00af, 59, degrees, end color #ff00af
The pink and green angles also add up to 180, degrees because they are adjacent and form a straight line too.
start color #28ae7b, start text, g, r, e, e, n, space, a, n, g, l, e, end text, end color #28ae7b, equals, 180, degrees, minus, start color #ff00af, 59, degrees, end color #ff00af, equals, start color #28ae7b, 121, degrees, end color #28ae7b
The measure of angle x, equals, start color #28ae7b, 121, degrees, end color #28ae7b.

### Practice

Problem 2A
What is the measure of angle x?
degrees

Want to try more problems like this? Check out this exercise.