A quadrilateral has four points A(0,1), B(1,3), C(5,2) and D(4,1) as coordinates, how do I find the area?
+309 Answer: \(6.5\) \(units²\)
Solution:
I would think that the best way is to graph the shape (although there is probably some better way) and then to break it up into three triangles and a rectangle. You can find the area of a triangle by looking at the graph, or just by looking at its points. (1-0)(3-1)/2 = 1 for example on the first triangle. I'm not great at explaining, so sorry if this doesn't make sense.
Triangle 1: (0,1), (1,1), (1,3)
The area of Triangle 1 is 1 square unit.
Triangle 2: (1,3), (1,2), (5,2)
The area of Triangle 2 is 2 square units.
Triangle 3: (5,2), (4,2), (4,1)
The area of Triangle 3 is 0.5 square units.
Rectangle: (1,1), (1,2), (4,2), (4,1)
The area of the rectangle is 3 square units.
Adding them all up you get 1 + 2 + 0.5 + 3 = \(6.5\) \(units²\)
