6.3 Areas of Polygons
(A) Area of Triangle
Area of Triangle
1. When the given points are taken in an anticlockwise direction the result is positive; taken in a clockwise direction the result is negative. The answer for the area must be given as a positive value.
Calculate the area of ∆ ABC with the vertices A (-5, 5), B (-2, -4),
C (4, -1).
(B) Area of Quadrilateral
Area of Quadrilateral
(C) If the points A, B and C are collinear, then the area of ∆ ABC is 0.
Find the values of k if the points P (2, 1), Q (6, k) and R (3k, ) are collinear.