module ComprehensionCheck where
    -- Exercises: Comprehension Check
    -- #1.
    half :: Fractional a => a -> a
    half x = x / 2

    square :: Num a => a -> a
    square x = x * x

    -- #2.
    area :: Floating a => a -> a 
    area r = 3.14 * r * r

    -- #3.
    area' :: Floating a => a -> a 
    area' r = pi * r * r