if ∆ is the area and 2s is the perimeter of atriangle then ∆

Sorry dear the question seems incomplete. Otherwise such questions I think are from Heron formula topic. So you can try using it to solve the above query. If you are trying to find ∆ in the above case, then simply you can put s= 2s/2 and put its value in heron formula. Note that in heron formula s is half of perimeter. So if perimeter is 2s then its half will be equal to s only.

Now if we put area and put value of s we will get a relation from heron formula.

I hope this will help or else you can complete the query and let me know what you want to find so I can assist more :)