Answer
$20$ square units
Work Step by Step
Area of a parallelogram with vertices $ABCD$ is defined as:
$|\overrightarrow{AB} \times \overrightarrow{BC}|$
Here,
$\overrightarrow{AB}=\lt -1-(-3),3-0 \gt= \lt 2,3 \gt$
$\overrightarrow{BC} =\lt 3-(-3),-1-0 \gt= \lt 6,-1 \gt$
$\overrightarrow{AB} \times \overrightarrow{BC}=\lt 6,-1 \gt \times \lt 2,3 \gt $
$=-(1)2-(6)3$
$=-2-(-18)$
$=-20$
$|\overrightarrow{AB} \times \overrightarrow{BC}| = |-20|$
$=20$ square units