I tried this question a lot of time and few day's earlier I also solved it correctly but I don't know why I am not able to solve it now. I can't get what link I am missing.
ques: 2 moles of helium gas undergo a cyclic process as shown. Assuming the gas to be ideal calculate the net change in heat energy, the net work done, the net change in internal energy
![enter image description here][1]  


  [1]: https://i.sstatic.net/vP9J5.png
If any one would just be able to give me the basics to approach the ques this will also help me?