Remember that
If two figures are similar, then the ratio of its perimeters is proportional, and this ratio is called the scale factor
so
In this problem
triangle GHK is similar to triangle JMP
that means
GH/JM=HK/MP=GK/JP=(PerimeterGHK)/(Perimeter JMP)
so
GH/JM=(PerimeterGHK)/(Perimeter JMP)
substitute given values
6/9=39/(Perimeter JMP)
solve for perimeter JMP
(Perimeter JMP)=(39*9)/6
(Perimeter JMP)=58.5 in
