private void Calculate_Click(object sender, EventArgs e)
{
   rectangle rect = new rectangle();
   rect.X = System.Convert.ToInt16(textBox1.Text, 10);
   rect.Y = System.Convert.ToInt32(textBox2.Text, 10);
   rect.calculateAera();
   rect.calculatePrime();
   label3.Text = "Area =" + System.Convert.ToString(rect.getArea()) + "  Prime=" + System.Convert.ToString(rect.getPrime());
}
