If \[p(z_1)\] ,\[q(z_2)\] and \[r(z_2)\] are the coordinates of the triangle then area of triangle is given by\[ \begin{vmatrix} z_1& \bar{z_1} & 1 \\ z_2 & \bar{z_2} & 1 \\ z_3& \bar{z_3} & 1 \\ \end{vmatrix}\]
where \[ z_1=a+ib\] \[ \bar{z_1}=a-ib\]\[ \]
\[ z_2=c+id\] \[ \bar{z_2}=c-id\]
\[ z_3=p+iq\] \[ \bar{z_3}=p-iq\]
