Write a program which takes 6 integers a, b, c, d, e, f - the coordinates of the vertices of the triangle (a, b), (c, d) and (e, f), and prints the value of its area. The coordinates of the vertices of the triangle are numbers in the range from -100 to 100. For example, for numbers 0 0 0 3 5 0 Your program should print 7.5, but for numbers 0 0 2 2 4 0 Your program should print 4.