Answer to Question #155244 in Java | JSP | JSF for joy

Question

Write a java code that finds out the area of three geometric shape: Circle, Triangle, Square. Give the user an option to select which geometric shape's area he/she wants to find out. Based on the choice take necessary input and find out the result. Use different area method for each geometric shape. Print the result in main method.

Answer 1

package com.company;

import java.util.Scanner;

public class Main {
    public static class Circle {
        private final double radius;

        public Circle(double radius) {
            this.radius = radius;
        }

        public double CalculateArea() {
            return Math.PI * radius * radius;
        }
    }

    public static class Triangle {
        private final double firstSide,secondSide, thirdSide;

        public Triangle(double firstSide, double secondSide, double thirdSide) {
            this.firstSide = firstSide;
            this.secondSide = secondSide;
            this.thirdSide = thirdSide;
        }

        public double CalculateArea() {
            //Heron's formula
            double semiPerimeter = (firstSide + secondSide + thirdSide) / 2.;
            return Math.sqrt(semiPerimeter * (semiPerimeter - firstSide) * (semiPerimeter - secondSide) * (semiPerimeter - thirdSide));
        }
    }

    public static class Square {
        private final double side;

        public Square(double side) {
            this.side = side;
        }

        public double CalculateArea() {
            return side * side;
        }
    }


    public static void main(String[] args) {
       System.out.println("Select needed shape: 1 for circle, 2 for triangle, 3 for square:");

        Scanner scanner = new Scanner(System.in);
        int choice = scanner.nextInt();
        switch (choice) {
            case 1 -> {
                System.out.println("Write circle radius:");
                double radius = scanner.nextDouble();
                Circle circle = new Circle(radius);
                System.out.println("Circle area is " + circle.CalculateArea());
            }
            case 2 -> {
                System.out.println("Write triangle sides separated by space:");
                double firstSide = scanner.nextDouble();
                double secondSide = scanner.nextDouble();
                double thirdSide = scanner.nextDouble();
                Triangle triangle = new Triangle(firstSide, secondSide, thirdSide);
                System.out.println("Triangle area is " + triangle.CalculateArea());
            }
            case 3 -> {
                System.out.println("Write square side:");
                double side = scanner.nextDouble();
                Square square = new Square(side);
                System.out.println("Square area is " + square.CalculateArea());
            }
            default -> System.out.println("Please follow the instructions above");
        }
    }
}