Image is question

M =  (3, 5)      N  = (9,2)   L  =  (-3,2)

Distance from  M to N  =  sqrt  [ (9 - 3)^2 + ( 5 - 2)^2 ]  = sqrt [ 36 + 9 ] = sqrt (45 )

Because of symmetry.....the distance from M to L  is the same

Distance from  L to N  =  9 - (-3)  = 12

So....the perimter is  2sqrt (45) + 12   ≈  25 units  (to the nnearest unit )