Respuesta :

Answer:

6

Step-by-step explanation:

Let line WY be the line of reflection

RR has the midpoint at Z.

In other words, the line:  =

SS is another line

It has a midpoint at X. In other words, line SX =

If SS =  12, then the line SX =

Because the shape is a parallelogram, it means that RZ = SX = 6