(Geometry: area of a triangle) 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: s= (side 1 + side2 + side 3)/2; area = s(s - sidel)(s - side 2)(s - side) Here is a sample run: Enter three points for a triangle: 1.5 -3.4 4.6 5 9.5 -3.4 - The area of the triangle is 33.6