Consider the triangle with vertices P(5, −2), Q(9, 3) and R(1, 4).
(a) Decide whether listing the vertices in the order P, Q, R produces a positive or a negative signed area. Justify your conclusion without changing the coordinates.
(b) Find the absolute value of the area of the triangle.
(c) Arrange the three vertices so that they appear in anti-clockwise order beginning with P, and write down this new sequence.