The easiest way is to find all it's factors.
Factors:
1,2,3,4,5,6,9,10,12,15,18,20,30,36,45,60,90,180
Then pair them with it's corespondent:
Answer:
1,180
2,90
3,60
4,45
5,36
6,30
9,20
10,18
12,15
The premier of a rectangle is length times width so if you multiply each corespondent together then you would get 180.
