[Java] 13. Area Of Figures

import java.util.Scanner;

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

        String figures = scanner.nextLine();

        if (figures.equals("square")) {
            double a = Double.parseDouble(scanner.nextLine());
            //System.out.println(a*a);
            double s = a*a;
            System.out.printf("%.3f", s);
        } else if (figures.equals("rectangle")) {
            double a = Double.parseDouble(scanner.nextLine());
            double b = Double.parseDouble(scanner.nextLine());
            //System.out.println(a*b);
            double s = a*b;
            System.out.printf("%.3f", s);
        } else if (figures.equals("circle")) {
            double r = Double.parseDouble(scanner.nextLine());
            //System.out.println(Math.PI*r*r);
            double s = Math.PI*r*r;
            System.out.printf("%.3f", s);
        } else if (figures.equals("triangle")) {
            double a = Double.parseDouble(scanner.nextLine());
            double h = Double.parseDouble(scanner.nextLine());
            //System.out.println(a*h/2);
            double s = a*h/2;
            System.out.printf("%.3f", s);
        }

    }
}