ProgBasicsJavaBook3.1SimpleConditions13AreaOfFigures

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        String figure = scanner.nextLine();

        double cubicMetres = 0;

        if (figure.equalsIgnoreCase("square")) {
            double a = Double.parseDouble(scanner.nextLine());
            cubicMetres = a * a;
            System.out.printf("%.3f", cubicMetres);
        } else if (figure.equalsIgnoreCase("rectangle")) {
            double a = Double.parseDouble(scanner.nextLine());
            double b = Double.parseDouble(scanner.nextLine());
            cubicMetres = a * b;
            System.out.printf("%.3f", cubicMetres);
        } else if (figure.equalsIgnoreCase("circle")) {
            double radius = Double.parseDouble(scanner.nextLine());
            cubicMetres = radius * radius * Math.PI;
            System.out.printf("%.3f", cubicMetres);
        } else if (figure.equalsIgnoreCase("triangle")) {
            double a = Double.parseDouble(scanner.nextLine());
            double height = Double.parseDouble(scanner.nextLine());
            cubicMetres = a * (height / 2);
            System.out.printf("%.3f", cubicMetres);
        }


    }
}