(Geometry: polygon subareas) A convex four-vertex polygon is divided into four triangles, as shown in Figure 8.9. Write a program that prompts the user to enter the coordinates of four vertices and...

(Geometry: polygon subareas) A convex four-vertex polygon is divided into four triangles, as shown in Figure 8.9.

Write a program that prompts the user to enter the coordinates of four vertices and displays the areas of the four triangles in increasing order. Here is a sample run: