1) Work done during the process from A to B = WAB
WAB = area ABKLA
(∴ because area under p-v curve gives work done)

Since gas expands during this process, hence WAB = 9×10-3J
2) Work done during the process from B to C(compression) is WBC = -area BCLK ( - ve because gas compresses during BC)
= - KL × LC
WBC = -3×10-3×2
= - 6×10-3J
3) Work done during the process from C to A :-
As there is no change in volume of gas in this process, WCA = O
So, net work done during the complete cycle = WAB + WBC +WCA
= 9×10-3-6×10-3+0
Net work done = 3×10-3J