Answer:
Reflection.
Explanation:
Reflection moves points across a specified line so that the line is the perpendicular bisector of each line segment connecting corresponding pre-image and image points.
On the other hand, "Translation" moves points the same distance along lines that are parallel to each other while "Rotation" moves points along concentric circles and through the same angle of rotation.
At an angle of 90°, a line of reflection intersects the line segments connecting corresponding points of the pre-image under a reflection.
Basically, a reflection allows us to flip an object or figure across a line, point or plane without any change in its shape or size.
Hence, to reflect an object or a figure such as a triangle simply means that its mirror image would be produced with respect to a line; this line is generally referred to as the line of reflection.