It's really easy to define the functions.
Function GetAreaOfARectangle(ByVal Edge1 As Integer, ByVal Edge2 As Integer) As Integer
Return Edge1 * Edge2
End Function
Dim Area As Integer = GetAreaOfARectangle(5, 8)
Console.Writeline(Area) 'Output: 40
Function Age(ByVal YourAge As Integer) As String
Select Case YourAge
Case Is < 18
Return("You are younger than 18! You are teen!")
Case 18 to 64
Return("You are older than 18 but younger than 65! You are adult!")
Cas...
