import Control.Applicative
import Control.Monad
import Text.Printf

main :: IO ()
main = do
  n <- readLn
  solve <$> replicateM n (getLine >> replicateM 6 f) >>= mapM_ (printf "%f\n")
  where
    f = map read <$> words <$> getLine

solve :: [[[Double]]] -> [Double]
solve = map f
  where
    f = minimum . filter (> 0) . map ang . filter (\[x, y] -> x < 0 && y > 0)

ang :: [Double] -> Double
ang [x, _] = 180.0 * acos x / pi - 120.0