In the diagram, the four points have coordinates $A(0,1)$, $B(1,3)$, $C(5,2)$, and $D(4.5,0)$. What is the area of quadrilateral $ABCD$?
Here is what I would do: area of red rectangle = 5 x 3 = 15 units^2
then subtract each of the right triangles area = 1/2 b * h
15 - 1 - 2 - 1/2 - 2.25 = 9.25 units^2
Here is what I would do: area of red rectangle = 5 x 3 = 15 units^2
then subtract each of the right triangles area = 1/2 b * h
15 - 1 - 2 - 1/2 - 2.25 = 9.25 units^2