07. 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 side = Double.parseDouble(scanner.nextLine());
            System.out.println(side * side);
        } else if (figures.equals("rectangle")) {
            double base = Double.parseDouble(scanner.nextLine());
            double height = Double.parseDouble(scanner.nextLine());
            System.out.println(base * height);
        } else if (figures.equals("circle")) {
            double radius = Double.parseDouble(scanner.nextLine());
            System.out.println(Math.PI * radius * radius);
        } else if (figures.equals("triangle")) {
            double base = Double.parseDouble(scanner.nextLine());
            double height = Double.parseDouble(scanner.nextLine());
            System.out.println(base * height / 2);
        }
    }
}