Find the perimeter of the given triangle kjn if kjn congruent lmn, kj = 17.5 lm=10 mn=8 and nl=6

I supposed you mean similar and not congruent.

If kjn ≡ lmn, the kj would be equal to lm which in your question, is not

Assumed kjn is similar to lmn

scale = 17.5 : 10 = 1.75

Therefore,

kj = 17.5 cm (given)

jn = 8 x 1.75 = 14 cm

kn = 6 x 1.75 = 10.5 cm

Perimeter = 17.5 + 14 + 10.5 = 42 cm

Answer: 42 cm