Use the formula given in Exercise 14(b) to calculate the area of the triangle with verti...

Use the formula given in Exercise 14(b) to calculate the area of the triangle with vertices (1, -4), (5, 3), and (13, 17). What do you conclude?

Reference

(b) Calculate the area of the remaining triangle in Exercise 13 by using the following formula for the area A of a triangle with vertices

The derivation of this formula is given in Exercise 34.