Given a reference triangle △ABC, a reflection triangle △A′B′C′ is generated by reflecting each vertex about the opposite side, for example A′ is generated by reflecting vertex A about side BC. Now, suppose the vertices A′, B′ and C′ are given, how can you find the original vertices of the original triangle △ABC?
Isn't it just the midpoints of the sides of triangle A'B'C'? This seems too easy.