i need help with this

Question

Shawn wants to make the perimeter of the fence in his backyard 2.5 times the size it currently is. What scale factor should he use to dilate the dimensions of the fence?

a	Scale factor of 5
b	Scale factor of 2.5
c	Scale factor of 3
d	Scale factor of 6.25

Answer 1

scale factor of 2.5 to increase

but scale factor of 1/2.5 to dilate the dimensions = .4

b) is best choice

d) looks good if the problem had said area instead of perimeter, as 2.5x2.5 = 6.25

all depends on shape of the fence rectangle? square? circle? triangle? half circle?