## Detailed description

Two diagrams.

- Left a triangle ABC with interior angles α at A, β at B and γ at C.
- Right line with point A and two rays from A. Angles marked β, γ and α.

Two diagrams.

- Left a triangle ABC with interior angles α at A, β at B and γ at C.
- Right line with point A and two rays from A. Angles marked β, γ and α.