Imports System

Public Module Module1

    Public Sub Main()

        Console.WriteLine("1. area del rectangulo 2. area del triangulo 3. area del circulo")

        'declaramos la variable opcion cono entero

        dim opcion as integer

        opcion = console.ReadLine()

        select opcion 

        Case 1 

            dim a,b,r as integer

            Console.WriteLine("Ingrese altura")

            a = Console.ReadLine()

            Console.WriteLine("Ingrese base")

            b = Console.ReadLine()

            r = a*b

            Console.WriteLine("EL area es: "&r)

        Case 2 

            dim a,b,r as integer

            Console.WriteLine("Ingrese altura")

            a = Console.ReadLine()

            Console.WriteLine("Ingrese base")

            b = Console.ReadLine()

            r = (a*b)/2

            Console.WriteLine("EL area es: "&r)

        Case 3 

            dim r,res as double

            Console.WriteLine("ingrese radio")

            r = Console.ReadLine()

            res = (r*r)*3.1416

            Console.WriteLine("el area es:" &res)

        end select

    End Sub

End Module