Question -
Answer -
Let ABCD be the given quadrilateral with vertices A (–4, 5), B (0, 7), C (5, –5), and D (–4, –2).
Then, by plotting A, B, C, and D on the Cartesian plane and joining AB, BC, CD, and DA, the given quadrilateral can be drawn as
To find the area ofquadrilateral ABCD, we draw one diagonal, say AC.
Accordingly, area (ABCD)= area (ΔABC) + area (ΔACD)
We know that the area ofa triangle whose vertices are (x1, y1),(x2, y2), and (x3, y3)is 
Therefore, area of ΔABC
Area of ΔACD
Thus, area (ABCD)