private void button1_Click(object sender, EventArgs e)
{
string result = selectedShape.CalcArea().ToString();
if (result == InformationString.ConditionOfResults)
{
MessageBox.Show(InformationString.IncorrectValue, InformationString.TitleOfMessagge,
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
else
{
tbResult.Text = result;
}
}