One mole of an ideal gas with $=1\mathrm{.}4$ is taken through the cyclic process depicted in Fig. $2.$ From A to B it undergoes an isptherrual expansion.

$(6$ pts$)($a$)$ Calculate the work done by the gas along each segment $AB,BC$ and $CA$ and add these values to get the total work.

$(6$ pts$)($b$)$ Find the heat absorbed per cycle by calculating the heat transferred in each segment.

$(6$ pts$)($c$)$ Consider the relationship $(">","<mi\; id="EditorElement\_379396">"</mi>$ or $"=)$ between the answers of parts $($a$)$ and $($b$),$ explain it by the $1^{st}$ law.

$(3$ pts$)($d$)$ Find the efficiency.