By comparing the 4 vertices you can determine the rectangle x-length and y-length. The coordinate for the vertice is: 1,+4i -2, +4i -2, -3i 1, -3i
From the coordinate, you can see there are 2 x coordinate(1 and -2) and 2 y coordinate(4i and -3i) that used. The x-length would be: 1 - (-2)= 3 The y-length would be: 4i- (-3i)= 7i
Then the area of the rectangle would be: area= x-length * y-length= 3*7=21
