Answer to Question #291181 in Java | JSP | JSF for yash

Question

 Create a public interface Triangle, add the following method signatures:  

• double area(): calculates and returns the area of a triangle. 
• double perimeter(): calculates and returns the perimeter of a triangle.   

Create a public abstract class Isosceles that implements Triangle and implements following method: 

• double perimeter(): calculates and returns the perimeter of a triangle 
• add fields as private double longside, equalSide. Use getter() and setter() methods to access them.  

Create a public interface Right that extends Triangle, add one more method signature:  

• double[] angles(): returns an array of measures of three interior angles.  

 

Create a public class RightIsosceles that extends Isosceles and implements interface Right:  

• double area(): calculates and returns the area of a triangle.  
• double[] angles(): returns an array of measures of three interior angles fields: longside, equalSide.  

Create the object of class RightIsosceles and print area, perimeter and angles of RightIsosceles triangle. 

Answer 1

interface Triangle {
	// double area(): calculates and returns the area of a triangle.
	double area();


	// double perimeter(): calculates and returns the perimeter of a triangle.
	double perimeter();
}


interface Right extends Triangle {
	// double[] angles(): returns an array of measures of three interior angles.
	public double[] angles();
}


abstract class Isosceles implements Triangle {
	// fields as private double longside, equalSide. Use getter() and setter()
	// methods to access them.
	private double longside;
	private double getEqualSide;


	public Isosceles() {


	}


	public Isosceles(double longside, double equalSide) {
		this.longside = longside;
		this.getEqualSide = equalSide;
	}


	// double perimeter(): calculates and returns the perimeter of a triangle
	public double perimeter() {
		return longside + 2 * getEqualSide;
	}


	/**
	 * @return the longside
	 */
	public double getLongside() {
		return longside;
	}


	/**
	 * @param longside the longside to set
	 */
	public void setLongside(double longside) {
		this.longside = longside;
	}


	/**
	 * @return the equalSide
	 */
	public double getEqualSide() {
		return getEqualSide;
	}


	/**
	 * @param equalSide the equalSide to set
	 */
	public void setEqualSide(double equalSide) {
		this.getEqualSide = equalSide;
	}
}


class RightIsosceles extends Isosceles implements Right {
	public RightIsosceles(double longside, double equalSide) {
		super(longside, equalSide);
	}


	@Override
	public double area() {
		double s = (this.getEqualSide() + this.getEqualSide() + this.getLongside()) / 2;
		return Math.sqrt(s * (s - this.getEqualSide()) * (s - this.getEqualSide()) * (s - this.getLongside()));
	}


	@Override
	public double[] angles() {
		double _angles[] = { 90, 45, 45 };
		return _angles;
	}


}


public class App {


	/**
	 * The start point of the program
	 * 
	 * @param args
	 * 
	 */
	public static void main(String[] args) {
		RightIsosceles _RightIsosceles = new RightIsosceles(Math.sqrt(2) * 10, 10);


		System.out.println("Area: " + _RightIsosceles.area());
		System.out.println("Perimeter: " + _RightIsosceles.perimeter());
		System.out.println("Angles: " + _RightIsosceles.angles()[0] + ", " + _RightIsosceles.angles()[1] + ", "
				+ _RightIsosceles.angles()[0]);


	}
}