7. Лица на фигури

Sub Demo()
    Dim result As Double
    result = ReturnArea("triangle", 4.5, 20)

    Debug.Print result
End Sub

Function ReturnArea(typeFigure As String, paramOne As Double, Optional paramTwo As Double)
    Select Case (typeFigure)
        Case "square"
            ReturnArea = paramOne * paramOne
        Case "circle"
            ReturnArea = WorksheetFunction.Pi * paramOne * paramOne
        Case "rectangle"
            ReturnArea = paramOne * paramTwo
        Case "triangle"
            ReturnArea = paramOne * paramTwo / 2
    End Select

End Function