Sphere, float Learn programming Visual Basic (VB.net)

Imports System
Public Class exercise59
    Public Shared Sub Main()
        Dim radius As Single
        Dim pi As Single = 3.1415926535F
        Console.Write("Radius? ")
        radius = Convert.ToSingle(Console.ReadLine())
        Console.WriteLine(4 * pi * (radius * radius))
        Console.WriteLine(4 / 3 * pi * (radius * radius * radius))
    End Sub
End Class