06. Area of Figures

import java.util.Scanner;

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

        String A = scanner.nextLine();

        if ( A.equals("square")){
            double A1 = Double.parseDouble(scanner.nextLine());
            System.out.printf("%.3f", A1*A1);
        }else if (A.equals("rectangle")) {
            double AR = Double.parseDouble(scanner.nextLine());
            double BR = Double.parseDouble(scanner.nextLine());
            System.out.printf("%.3f", AR*BR);
        }else if (A.equals("circle")){
            double R = Double.parseDouble(scanner.nextLine());
            System.out.printf("%.3f", Math.PI*(R*R));
        }else if (A.equals("triangle")) {
            double R1 = Double.parseDouble(scanner.nextLine());
            double R2 = Double.parseDouble(scanner.nextLine());
            System.out.printf("%.3f", (R1*R2)/2);
        }
    }
}