Question

Why is my program returning 0 for the area of a triangle?

public class GeometricObjects {

   private String color = " white ";
    private boolean filled;
    private java.util.Date dateCreated;

    public GeometricObjects() {
        dateCreated = new java.util.Date();
    }

    public GeometricObjects(String color, boolean filled) {
        dateCreated = new java.util.Date();
        this.color = color;
        this.filled = filled;
    }

    public String getColor() {
        return color;
    }

    public void setColor(String color) {
        this.color = color;
    }

    public boolean isFilled() {
        return filled;
    }

    public void setFilled(boolean filled) {
        this.filled = filled;
    }

    public java.util.Date getDateCreated() {
        return dateCreated;
    }

    public String toString() {
        return "Created on " + dateCreated + "\n color: " + color + " and filled ";               
   }
}

Below is the class containing the formula for the area of a triangle:

import java.lang.Math;

public class Triangle extends GeometricObjects {
  
   private double side1, side2, side3 = 1.0;

    public Triangle() {
    }

    public Triangle(double side1, double side2, double side3) {
        this.side1 = side1;
        this.side2 = side2;
        this.side3 = side3;
    }

    public double setSide1() {
        return side1;
    }

    public double setSide2() {
        return side2;
    }

    public double setSide3() {
        return side3;
    }

    public void getSide1(double side1) {
        this.side1 = side1;
    }

    public void getSide2(double side2) {
        this.side2 = side2;
    }

    public void getSide3(double side3) {
        this.side3 = side3;
    }
  
    public double getPerimeter() {
        return side1 + side2 + side3;
    }

    public double getArea() {
        double p = (side1 + side2 + side3) / 2;
        double i = (p * ((p - side1) * (p - side2)
               * (p - side3)));
        double area = Math.sqrt(i);
        return area;
    }

    public String toString() {
    return "Triangle: Side 1 = " + side1 + " Side 2 = " + side2
           + " Side 3 = " + side3;
    }
}   

And finally, below is my code for the test class:

import java.util.Scanner;

public class TestGeometricObjects {
  
   private double side1, side2, side3, length, width = 1.0;

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

        System.out.println("Enter three sides of the triangle: ");
        double side1 = input.nextDouble();
        double side2 = input.nextDouble();
        double side3 = input.nextDouble();

        System.out.println("Enter the color of the triangle: ");
        String triangleColor = input.next();

        System.out.println("Is the triangle filled? Reply with"
            + " 'True' or 'False' ");
        boolean triangleFilled = input.nextBoolean();
      
       Triangle triangle = new Triangle(side1, side2, side3);
       triangle.setFilled(triangleFilled);
       triangle.setColor(triangleColor);
          
       System.out.println("The triangle's 3 sides are " + side1 + ", " + side2 +
               ", " + side3);
       System.out.println("The triangle's area is " + triangle.getArea());
       System.out.println("The triangle's perimeter is " + triangle.getPerimeter());
       System.out.println("The triangle's color is " + triangle.getColor());
       System.out.println("Is the triangle filled? " + triangle.isFilled());
     
       System.out.println("Enter the length and width of a rectangle: ");
       double length = input.nextDouble();
       double width = input.nextDouble();
     
       System.out.println("Enter the color of the rectangle: ");
        String rectangleColor = input.next();
      
       System.out.println("Is the rectangle filled? Reply with"
                + " 'True' or 'False' ");
       boolean rectangleFilled = input.nextBoolean();
     
       Rectangle rectangle = new Rectangle(length, width);
       rectangle.setFilled(rectangleFilled);
       rectangle.setColor(rectangleColor);
     
       System.out.println("The rectangle's length is " + length +
               " and the rectangle's width is " + width);
       System.out.println("The rectangle's area is " + rectangle.getRectArea());
       System.out.println("The rectangle's perimeter is " + rectangle.getRectPerimeter());
       System.out.println("The rectangle's color is " + rectangle.getColor());
       System.out.println("Is the rectangle filled? " + rectangle.isFilled());
      
   }
}

Answer 1

//Its working fine your have to enter Sides of triangle./
//its returning correct area.
//Add rectangle class also .

public class GeometricObjects {
   private String color = " white ";
    private boolean filled;
    private java.util.Date dateCreated;
    public GeometricObjects() {
        dateCreated = new java.util.Date();
    }
    public GeometricObjects(String color, boolean filled) {
        dateCreated = new java.util.Date();
        this.color = color;
        this.filled = filled;
    }
    public String getColor() {
        return color;
    }
    public void setColor(String color) {
        this.color = color;
    }
    public boolean isFilled() {
        return filled;
    }
    public void setFilled(boolean filled) {
        this.filled = filled;
    }
    public java.util.Date getDateCreated() {
        return dateCreated;
    }
    public String toString() {
        return "Created on " + dateCreated + "\n color: " + color + " and filled ";             
   }
}
import java.lang.Math;
public class Triangle extends GeometricObjects {
   private double side1, side2, side3 = 1.0;
    public Triangle() {
    }
    public Triangle(double side1, double side2, double side3) {
        this.side1 = side1;
        this.side2 = side2;
        this.side3 = side3;
    }
    public double setSide1() {
        return side1;
    }
    public double setSide2() {
        return side2;
    }
    public double setSide3() {
        return side3;
    }
    public void getSide1(double side1) {
        this.side1 = side1;
    }
    public void getSide2(double side2) {
        this.side2 = side2;
    }
    public void getSide3(double side3) {
        this.side3 = side3;
    }
    public double getPerimeter() {
        return side1 + side2 + side3;
    }
    public double getArea() {
        double p = (side1 + side2 + side3) / 2;
        double i = (p * ((p - side1) * (p - side2)* (p - side3)));
        double area = Math.sqrt(i);
        return area;
    }
    public String toString() {
    return "Triangle: Side 1 = " + side1 + " Side 2 = " + side2
           + " Side 3 = " + side3;
    }
}
import java.util.Scanner;
public class TestGeometricObjects {
   private double side1, side2, side3, length, width = 1.0;
   public static void main(String[] args) {
       Scanner input = new Scanner(System.in);
        System.out.println("Enter three sides of the triangle: ");
        double side1 = input.nextDouble();
        double side2 = input.nextDouble();
        double side3 = input.nextDouble();
        System.out.println("Enter the color of the triangle: ");
        String triangleColor = input.next();
        System.out.println("Is the triangle filled? Reply with"
            + " 'True' or 'False' ");
        boolean triangleFilled = input.nextBoolean();
       Triangle triangle = new Triangle(side1, side2, side3);
       triangle.setFilled(triangleFilled);
       triangle.setColor(triangleColor);
       System.out.println("The triangle's 3 sides are " + side1 + ", " + side2 +
               ", " + side3);
       System.out.println("The triangle's area is " + triangle.getArea());
       System.out.println("The triangle's perimeter is " + triangle.getPerimeter());
       System.out.println("The triangle's color is " + triangle.getColor());
       System.out.println("Is the triangle filled? " + triangle.isFilled());
       System.out.println("Enter the length and width of a rectangle: ");
       double length = input.nextDouble();
       double width = input.nextDouble();
       System.out.println("Enter the color of the rectangle: ");
        String rectangleColor = input.next();
       System.out.println("Is the rectangle filled? Reply with"
                + " 'True' or 'False' ");
       boolean rectangleFilled = input.nextBoolean();
       Rectangle rectangle = new Rectangle(length, width);
       rectangle.setFilled(rectangleFilled);
       rectangle.setColor(rectangleColor);
       System.out.println("The rectangle's length is " + length +
               " and the rectangle's width is " + width);
       System.out.println("The rectangle's area is " + rectangle.getRectArea());
       System.out.println("The rectangle's perimeter is " + rectangle.getRectPerimeter());
       System.out.println("The rectangle's color is " + rectangle.getColor());
       System.out.println("Is the rectangle filled? " + rectangle.isFilled());
   }
}