Question

Find the area of the quadrilateral $ABCD$ given $A(1,2),B(-3,4),C(-5,-6)$ and $D(4,-1$).

• A. $20$ sq. units
• B. $43$ sq. units
• C. $55$ sq. units
• D. $32$ sq. units

Answer 1

The correct option is B $43$ sq. units

We see that the points given are in order.
So, area of the quadrilateral ABCD
$=\frac{1}{2}\left[\right(4+18+5+8)-(-6-20-24-1\left)\right]$
$=\frac{1}{2}[35+51]=\frac{1}{2}\times 86=43$ sq.units
Alternatively, you can find area of quadrilateral by dividing it into two triangles.