What is the volume, in cubic inches, of the prism

Choose the triangle with x equal to 17.

Acable car begins its trip by moving up a hill. as it moves up, it gains elevation at a constant rate of 50 feet/minute until it reaches the peak at 2,000 feet. then, as the car moves down to the hill’s base, its elevation drops at the same rate.

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?