## Angle Geometry

On this page you will learn about:

- Classifying single angles
- Classifying pairs of angles
- Finding the value of a missing angle
- Check your understanding

## Classifying Angles

An angle describes an amount of turn or rotation, and is measured in

One complete turn or revolution is 360°

A protractor, like the one below, can be used to measure the size of any angle.

**degrees**(°). (1)One complete turn or revolution is 360°

A protractor, like the one below, can be used to measure the size of any angle.

## Complementary Angles

## Supplementary Angles

## Adjacent Angles

## Vertically Opposite Angles

Vertically Opposite Angles occur when two straight lines cross each other. The result is two pairs of equal angles that are opposite each other.

(5)

(5)

## Using Angle Geometry to Find Missing Values

## Find the missing variable, and give reasons.

## Find the missing variable, and give reasons.

## Find the missing variable, and give reasons.

a=110, because

b=70, because

(5)

*a*is vertically opposite 110°.b=70, because

*b*is supplementary to 110° and therefore adds to 180°.(5)