Triangle EFG is transformed to create triangle E'F'G'.Which transformation occurred?translationstretchrotationreflection

Answer: RotationStep-by-step explanation:From the given picture it can be seen that the size of both triangles are equal. [since both triangles are congruent by SSS congruence postulate]It means there is only rigid transformation has been applied. [Since rigid transformations preserves size] There are three common rigid transformations that are:-Reflection:- A reflection is a transformation that generally flips a shape over a line of reflection( acts as mirror) such that it produces the mirror image of the pre-image.Rotation:- A rotation rotate a figure about a fixed point .  It usually changes the orientation of the figure.Translation:- A translation is a transformation of a figure that moves each point of the figure(pre-image) a exact distance in a particular direction. Here orientation of figure remains unchanged .Since in transformation of Δ EFG to Δ E'F'G', its orientation got changed.So by the definition of rotation , when Δ EFG is transformed to create Δ E'F'G'  rotation transformation occurred.