@@ -0,0 +1,896 @@
+package ru.job4j;%0A%0A%0Apublic class Triangle %7B%0Apublic Point a;%0Apublic Point b;%0Apublic Point c;%0A%0Apublic Triangle(Point a, Point b, Point c) %7B%0Athis.a = a;%0Athis.b = b;%0Athis.c = c;%0A%7D%0A%0Apublic double area() %7B%0A//calculate the area%0Adouble side1= this.a.distanceTo(b);%0Adouble side2= this.b.distanceTo(c);%0Adouble side3= this.c.distanceTo(a);%0A%0A%0Adouble p=(side1 + side2+ side3)/2.0d;%0Adouble area = Math.sqrt(p * (p - side1) * (p - side2) * (p - side3));%0A%0Aif ((side1%3E=(side2+side3)) && (side2%3E=(side1+side3)) && (side3%3E=(side1+side2)))%0A%09%7B%0Areturn area;%0A%7D%0A%0Aelse %7B%0A%09System.out.print(%22 %22);%0A%7D%0A   return 0;%0A   %0A %7D%0A        %0A%09%0A    public static void main(String%5B%5D args) %7B    %0A        Point a = new Point(15d,10d);%0A        Point b = new Point(10d,5d);%0A        Point c = new Point(0d,10d);%0A%09%09Triangle triangle = new Triangle(a,b,c);%0A%09%09double result = triangle.area();%0A%09    System.out.println(result);%7D%09%0A        %09%09 %0A     %7D%0A

add triangle.java