# Related Angles Summary

- Author:
- Caribou Contests

- Topic:
- Angles

## Definitions

- α and δ are known as
**vertically opposite angles**. Vertically opposite angles are equal. β and γ, ε and θ, and ζ and η are also vertically opposite angles. - η and γ are
**corresponding angles**. Corresponding angles are equal. This is sometimes called the "F" pattern. θ and δ, ζ and β, and ε and α are also corresponding angles. - δ and ε are
**alternate angles**. Alternate angles are equal. This is sometimes called the "Z" pattern. γ and ζ are also alternate angles. - α and β are
**adjacent angles**. Adjacent angles are formed by the same two lines and add up to 180°. - δ and ζ are
**interior angles**. These add up to 180°. This is sometimes called the "C" pattern. ε and γ are also interior angles. - Any two angles that add up to 90° are known as
**complementary angles**. - Any two angles that add up to 180° are known as
**supplementary angles**.