Sign of work is positive for clockwise cyclic process for $\mathrm{V}$ vs $\mathrm{P}$ graph.
$\mathrm{W}=\frac{1}{2} \times(30-10) \times(30-10)=200 \mathrm{kPa}-\mathrm{dm}^3$
$=200 \times 1000 \mathrm{~Pa}-\mathrm{L}=2 \mathrm{~L}-\mathrm{bar}=200 \mathrm{~J}$