Nothing but the italicized text was given. I'm relying on the PV Diagram for an ideal otto cycle. i.e. http://www.grc.nasa.gov/WWW/K-12/airplane/otto.html, where 2/6, 3, 4, 5 are my a, b, c, d respectively. The only thing I know about enthalpy is what I've seen from some cambridge videos on...