//  Scott DeRuiter 9/22/2002
//  Heron.java
//  Asks for the side lengths of a triangle, then
//  calculates the area using Heron's formula.
//  7/15/2011 - Greenstein: Changed TextReader to Scanner, added import Math

import java.util.Scanner;
import java.lang.Math;

public class Heron   
{
	public static void main ( String [] args )   
	{

		double side1, side2, side3, semiperim, area;
		Scanner keyboard = new Scanner ( System.in );

		System.out.print ( "\n\nEnter the length of the first side  -> " );
		side1 = keyboard.nextDouble ( );
		System.out.print ( "\n\nEnter the length of the second side -> " );
		side2 = keyboard.nextDouble ( );
		System.out.print ( "\n\nEnter the length of the third side  -> " );
		side3 = keyboard.nextDouble ( );

		semiperim = ( side1 + side2 + side3 ) / 2.0;
		area = Math.sqrt(semiperim * (semiperim - side1) * 
			(semiperim - side2) * (semiperim - side3));

		System.out.println ( "\n\nHere is the information for your triangle:" );
		System.out.println ( "side1   : " + Format.right ( side1, 12, 3) );
		System.out.println ( "side2   : " + Format.right ( side2, 12, 3 ) );
		System.out.println ( "side3   : " + Format.right ( side3, 12, 3 ) );
		System.out.println ( "area    : " + Format.right ( area, 12, 3 ) );

	}
}