Elementary Programming; Exercise No. 17

Write a program that prompts the user to enter three points  (x1, y1) , (x2, y2) , (x3, y3) of a triangle and displays its area. The formula for computing the area of a triangle is:

Solution:

public static void main(String[] args) {

   Scanner scanner = new Scanner(System.in);

   double x1, y1, x2, y2, x3, y3; // variables to hold the points of the triangle

   double side1, side2, side3; // variables to hold the sides of the triangle

   double s, area;

   System.out.print("Enter x1 and y1:");

   x1 = scanner.nextDouble();

   y1 = scanner.nextDouble();

   System.out.print("Enter x2 and y2:");

   x2 = scanner.nextDouble();

   y2 = scanner.nextDouble();

   System.out.print("Enter x3 and y3:");

   x3 = scanner.nextDouble();

   y3 = scanner.nextDouble();

   side1 = Math.pow(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2), 0.5);

   side2 = Math.pow(Math.pow(x3 - x1, 2) + Math.pow(y3 - y1, 2), 0.5);

   side3 = Math.pow(Math.pow(x3 - x2, 2) + Math.pow(y3 - y2, 2), 0.5);

   s = (side1 + side2 + side3)/2;

   area = Math.pow(s * (s - side1) * (s - side2) * (s - side3), 0.5);

   System.out.print("The area of the triangle is " + area);

}