you might need to use the distance formula
for the distance betwen (x1,y1) and (x2,y2) is
[tex]D= \sqrt{(x1-x2)^2+(y1-y2)^2} [/tex]
so find disance between (-3,1) and (-1,3)
and (-1,3) and (3,1)
so
if we did input them
we would get [tex]6+2 \sqrt{2}+2 \sqrt{5} [/tex] which is the peirmiter
