Primary School⏱ 3 min

Vertical Angles

Proof by a half-turn

○Not Started
Vαβγδcommon vertex, arms are opposite rays
Rotate the second lineα = 50°

Rotate α a half turn about the vertex and watch where it lands.

α = γ50°
β = δ130°

Vertical angles share a vertex and their arms are opposite rays. They are always congruent.