It is true that corresponding points must be an equal distance from the Line of reflection. This is because in cases of reflection, the image is far behind the mirror or line of reflection as the object is in front of the mirror. What this proposition means is, the distance from the object to the line of reflection is equal to the distance between the reflection line and the image. There sizes are bound to be equal to, and hence the two corresponding points will be similar.
I don’t really understand I need more detail
145600 you just do 14560 times 1 and add a zero.