In the given elliptical P_V diagram :

The work done = area of P-V diagram :

\(a = \frac{V_1-V_1}{2}, b = \frac{P_2-P_1}{2}\)

W = \(\pi (\frac{V_2-V_1}{2}) (\frac{P_2-P_1}{2})\)

But the cyclic process is anticlockwise. Thus, the work done is negative.