package shape;

public interface Shape2 {
	public double getArea2();
}


package shape;

public class Rectangle implements Shape2{

	private double a;
	private double b;

	public double getA() {
		return a;
	}
	public void setA(double a) {
		this.a = a;
	}
	public double getB() {
		return b;
	}
	public void setB(double b) {
		this.b = b;
	}
	public Rectangle(double a, double b) {
		super();
		this.a = a;
		this.b = b;
	}
	@Override
	public double getArea2() {

		return a * b;
	}
}


package shape;

public class Triangle implements Shape2{
	private double c;
	private double d;
	@Override
	public double getArea2() {
		return c * d * 0.5;
	}
	public double getC() {
		return c;
	}
	public void setC(double c) {
		this.c = c;
	}
	public double getD() {
		return d;
	}
	public void setD(double d) {
		this.d = d;
	}
	public Triangle(double c, double d) {
		super();
		this.c = c;
		this.d = d;
	}

}



package shape;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		System.out.println("Введіть довжини прямокутника");
		double a = scn.nextDouble();
		double b = scn.nextDouble();
		System.out.println("Площа прямокутника " + new Rectangle(a, b).getArea2());
		System.out.println("Введіть довжини трикутника");
		double c = scn.nextDouble();
		double d = scn.nextDouble();
		System.out.println("Площа трикутника " + new Triangle(c, d).getArea2());
	}


}