Related Angles Summary

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.