**Answer**

Let the points (1, 5), (2, 3), and (- 2,-11) be representing the vertices A, B, and C of the given triangle respectively.Let A = (1, 5), B = (2, 3) and C = (- 2,-11)

Since AB + BC ≠ CA

Therefore, the points (1, 5), (2, 3), and ( - 2, - 11) are not collinear.