private void CalcularClick(Object sender, RoutedEventArgs e)
        {
            Esfera x = new Esfera();

            x.SetRaio(double.Parse(txtR.Text));
            txtA.Text = x.CalcArea().ToString("0.00");
            txtV.Text = x.CalcVolume().ToString("0.00");
        }
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            Esfera esfe = new Esfera();

            esfe.SetRaio(double.Parse(raio.Text));
            area.Text   = esfe.CalcArea().ToString();
            volume.Text = esfe.CalcVolume().ToString();
        }
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            Esfera x = new Esfera();

            x.SetRaio(double.Parse(r.Text));

            a.Text = x.CalcArea().ToString();
            v.Text = x.CalcVolume().ToString();
        }