Which transformation changes the position of an object without altering its size or shape?

The transformation that changes the position of an object without altering its size or shape is known as a rigid motion. Rigid motions include transformations such as translations, rotations, and reflections.

When an object undergoes a rigid motion, every point in the object moves in a specific way, while the distances between points and the angles remain constant. This means that the object maintains its size and shape throughout the transformation.

For instance, if you take a triangle and reflect it across a line, rotate it around a point, or slide it to a different location on the plane, the triangle itself doesn't change in size or form; only its position does. Rigid motions preserve the geometric properties of the object, reinforcing the definition of transformations that do not affect size or shape.

In contrast, scaling alters the size of an object, while translation specifically refers to sliding an object from one position to another. However, in the broader context of rigid motions, translation is a type of transformation included within that category. Thus, the distinction is that a rigid motion encompasses all forms of without size or shape alteration, making it the most encompassing and accurate choice in this context.