Similar Shapes: Shapes of different sized that have corresponding sides in equal proportion and identical corresponding angles. 

Scale Factor: A scale factor is when you enlarge a shape and each side is multiplied by the same number. This number is called the scale factor.  

Enlarge: to change the size of a shape (enlargement is not always making a shape bigger!)

Corresponding: Objects (or sides) that appear in the same place in two similar situations

Image: the picture or visual representation of the shape