Is there more information?
Those polygons are proportional 
The proportion is 4:2 to 16:8
For example, the small rectangle measure 4 x 2
If we multiply both lengths by 4, the result will be the lengths of the larger rectangle
 4 x 4 : 2 x 4
 16 : 8 
or if we divide the lengths of the larger polygon by 4, the result will be the lengths of the small rectangle.
What are the directions over this problem?
It says: The pairs of polygons below are. 
Ok, perfect
 The scale factor is the number 4 that we use to multiply the lengths
 1:4