Represent the above relationship between the number of triangles and the perimeter of the figures they form by filling in the table below. show your work. picture included

I'm not entirely sure the format you want the answer in but the table filled out is 

1 triangle/ perimeter of 17
2 triangles/ perimeter of 22
3 triangles/ perimeter of 27

The relationship is every time you add a triangle the perimeter goes up 5
So it's something like 

perimeter= 17+5(# of triangles)  

So if P=perimeter and T= # of additional triangles, the relationship would be

P= 17+5t

I hope this is what you're looking for!