GeometricShapes

import java.util.Scanner;

public class GeometryShapes {

    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        String yesOrNo;

        do {
            System.out.println("\nChoose a shape: ");
            System.out.println(" Circle\n" +
                    " Rectangle\n" +
                    " Triangle\n" +
                    " Trapezoid");

            System.out.print("Enter Your Choice: ");
            String shapeChoice = scan.next();

            if (!(shapeChoice.equalsIgnoreCase("circle")
                    || shapeChoice.equalsIgnoreCase("rectangle")
                    || shapeChoice.equalsIgnoreCase("triangle")
                    || shapeChoice.equalsIgnoreCase("trapezoid"))) {
                System.out.println("Invalid shape chosen.");
            } else { // if correct shape was chosen...
                System.out.print("Solve for area or volume? ");
                String choice = scan.next();

                if (choice.equalsIgnoreCase("volume")) {
                    System.out.println("Invalid choice made. " +
                            "Cannot calculate the volume of a 2D shape.");
                } else if (choice.equalsIgnoreCase("area")) {

                    double area;
                    switch (shapeChoice.toLowerCase()) {
                        case "circle":
                            System.out.print("What is the radius: ");
                            double r = Double.parseDouble(scan.next());
                            area = Math.PI * Math.pow(r, 3);
                            break;

                        case "rectangle":
                            System.out.print("What is the length: ");
                            double length = Double.parseDouble(scan.next());
                            System.out.println("What is the width: ");
                            double width = Double.parseDouble(scan.next());
                            area = length * width;
                            break;

                        case "triangle":
                            System.out.print("What is the base: ");
                            double base = Double.parseDouble(scan.next());
                            System.out.print("What is the height: ");
                            double height = Double.parseDouble(scan.next());
                            area = (1.0 / 2.0) * (base * height);
                            break;

                        case "trapezoid":
                            System.out.print("What is b1: ");
                            double b1 = Double.parseDouble(scan.next());
                            System.out.print("What is b2: ");
                            double b2 = Double.parseDouble(scan.next());
                            System.out.print("What is the height: ");
                            double heightOfTrapezoid = Double.parseDouble(scan.next());
                            area = (1.0 / 2.0) * ((b1 + b2) * heightOfTrapezoid);
                            break;
                        default:
                            area = 0.0;
                    } // end switch
                    System.out.printf("Area is: %,.2f\n", area);
                } else { // if neither area nor volume was chosen...
                    System.out.println("Invalid choice made. Choose either area or volume only.");
                } // end inner else
            } // end outer else

            System.out.print("\nWould you to continue (y or n): ");
            yesOrNo = scan.next().toLowerCase();
        } while (yesOrNo.charAt(0) == 'y');

    } // end main()
} // end class