private void calculateCircleCircuit() { if (circleCircuitCheckBox.Checked) { if (int.TryParse(circleRadiusTextBox.Text.Trim(), out radius)) { Figure2DService <Circle> circleService = new CircleService(); double circleCircuit = circleService.calculateCircuit(radius); String circuitResult = String.Format("{0}. Circle circuit is: {1} for radius: {2}", counter++, circleCircuit, radius); Console.WriteLine(circuitResult); result.Add(circuitResult); } } }