function bufferequal(feature){
  var ar = feature.area();
  var perim = feature.perimeter();

  var rooted = perim.pow(2).add(ar.multiply(16)).sqrt();
  var nomin = rooted.subtract(perim);

  var soln = nomin.divide(8);

  var buff = feature.buffer(soln);

  return buff;
}

var bufferedCollection = yourFeatureCollection.map(bufferequal);