public static void MainMenu() { WriteLine("Welcome to the Math assignment in C Sharp!"); WriteLine("Enter 1 to build a rectangle, 2 for a square, 3 for a triangle, 4 for an octagon or 5 for a times table."); WriteLine("Or enter 0 to exit."); var answer = ReadLine(); if (answer == "0") { WriteLine("Goodbye!"); Environment.Exit(0); } else if (answer == "1") { WriteLine("Enter the length of your rectangle: "); double length = 0; double width = 0; try { length = Convert.ToDouble(ReadLine()); } catch (SystemException) { WriteLine("Error! Invalid value. Going back to main menu..."); Menu.MainMenu(); } WriteLine("Enter the width of your rectangle: "); try { width = Convert.ToDouble(ReadLine()); } catch (SystemException) { WriteLine("Error! Invalid value. Going back to main menu..."); Menu.MainMenu(); } Rectangle rectangle = new Rectangle(length, width); WriteLine("The area of your rectangle is " + rectangle.GetArea()); rectangle.AcceptDetails(); rectangle.Display(); rectangle.DisplayInfo(); Menu.MainMenu(); } else if (answer == "2") { WriteLine("Enter the length and width of your square: "); double length = 0; try { length = Convert.ToDouble(ReadLine()); } catch (SystemException) { WriteLine("Error. Invalid value specified. Returning to main menu..."); Menu.MainMenu(); } var width = length; Square square = new Square(length, width); WriteLine("The area of your rectangle is " + square.GetArea()); square.AcceptDetails(); square.Display(); Menu.MainMenu(); } else if (answer == "3") { WriteLine("Enter the length of your triangle: "); double length = 0; double width = 0; try { length = Convert.ToDouble(ReadLine()); } catch (SystemException) { WriteLine("Error! Invalid value. Going back to main menu..."); Menu.MainMenu(); } WriteLine("Enter the width of your triangle: "); try { width = Convert.ToDouble(ReadLine()); } catch (SystemException) { WriteLine("Error! Invalid value. Going back to main menu..."); Menu.MainMenu(); } Triangle triangle = new Triangle(length, width); WriteLine("The area of your triangle is " + triangle.GetArea()); triangle.AcceptDetails(); triangle.Display(); Menu.MainMenu(); } else if (answer == "4") { WriteLine("Enter the side length of your octagon: "); double sidelength = 0; try { sidelength = Convert.ToDouble(ReadLine()); } catch (SystemException) { WriteLine("Error! Invalid value. Going back to main menu..."); Menu.MainMenu(); } Octagon octagon = new Octagon(sidelength); octagon.AcceptDetails(); octagon.Display(); Menu.MainMenu(); } else if (answer == "5") { WriteLine("Please enter your value for a times table."); double value = 0; try { value = Convert.ToDouble(ReadLine()); } catch (SystemException) { } TimesTable table = new TimesTable(value); table.Display(); Menu.MainMenu(); } else { WriteLine("Invalid response! Try again."); Menu.MainMenu(); } }