4. Given AABC with vertices A(2, 1), 3(7, 2) and (36, 3). Determine if AABC is a right triangle. If so, determine which the right angle is. You may only use vector tools to solve the question. [5] 5. Given the points A(1, 2, 0), 3(3, 2, 0), (3(1), 2, 3), and D (1, 0, 1), determine a unit vector that is perpendicular to both E and 53. [6]