◀ ▲ ▶Branches / Geometry / Elements-euclid / Book--1-plane-geometry / Definition: Exterior, Interior, Alternate and Corresponding Angles

Definition: Exterior, Interior, Alternate and Corresponding Angles

When a straight line intersects two other straight lines at two distinct points, between them are eight angles (see Fig.).

• Angles 1 and 2, 7 and 8 are called exterior angles;
• Angles 3 and 4, 5 and 6 are called interior angles;
• Angles 4 and 6, 3 and 5 are called alternate angles;
• Angles 1 and 5, 2 and 6, 3 and 8, 4 and 7 are called corresponding angles.

Mentioned in:

Propositions: 1 2

Thank you to the contributors under CC BY-SA 4.0!

Github:

non-Github:

@Calahan

@Casey

References

Adapted from CC BY-SA 3.0 Sources:

1. Callahan, Daniel: "Euclid’s 'Elements' Redux" 2014

Adapted from (Public Domain)

1. Casey, John: "The First Six Books of the Elements of Euclid"