Given ∆FPM ~ ∆DGV with a scale factor of 8:5. If the perimeter of ∆FPM is 72, what is the perimeter of ∆DGV?

Say the perimiter of DGV is P, then from the given, we know that FPM's Perimiter : DGV's Perimiter = 8:5

Substituing in, we have 72:P = 8:5. In the scale factor 8:5, we know that each unit is 9 for FPM, likewise, each unit for 5 would also be nine. In other words, solving it as an equation 72/p = 8/5 you obtain p = 45. 

Perimiter of DGV is 45 units.