public class Main
{
    public static void main( String[] args )
    {
        double a;

        a = triangleArea(3, 3, 3);
        System.out.println("A triangle with sides 3,3,3 has an area of " + a );

        a = triangleArea(3, 4, 5);
        System.out.println("A triangle with sides 3,4,5 has an area of " + a );

        a = triangleArea(7, 8, 9);
        System.out.println("A triangle with sides 7,8,9 has an area of " + a );

        System.out.println("A triangle with sides 5,12,13 has an area of " + triangleArea(5, 12, 13) );
        System.out.println("A triangle with sides 10,9,11 has an area of " + triangleArea(10, 9, 11) );
        System.out.println("A triangle with sides 8,15,17 has an area of " + triangleArea(8, 15, 17) );
    }

    public static double triangleArea( int a, int b, int c )
    {
        // the code in this function computes the area of a triangle whose sides have lengths a, b, and c
        double s, A;

        s = (a+b+c) / 2;
        A = Math.sqrt( s*(s-a)*(s-b)*(s-c) );

        return A;
        // ^ after computing the area, "return" it
    }
}