Tell whether the blue figure is a reflection of the red figure.
A reflection is a transformation representing a flip of a figure. Figures may be reflected in a point, a line, or a plane. When reflecting a figure in a line or in a point, the image is congruent to the preimage. A reflection maps every point of a figure to an image across a fixed line.
The blue figure is a reflection of the red figure because to each point in the red figure corresponds a symmetrical point in the blue figure.
So the blue figure is a reflection of the red figure