Answer
See answers.
Work Step by Step
The first segment is the cooling at constant pressure. Since the process is at a constant pressure, the path on the diagram is horizontal from V1 to 0.5V1. The second segment is the isothermal expansion. The temperature is constant, so the ideal gas law says that the product PV is constant. Since the volume is increased by a factor of 2, the pressure is halved during the process. (The second path is part of a hyperbola.)