What is the change in internal energy of the gas how much

Question

In the figure, 2.62 mole of an ideal diatomic gas can go from a to c along either the direct (diagonal) path ac or the indirect path abc. The scale of the vertical axis is set by p_ab = 4.89 kPa and p_c, = 2.20 kPa, and the scale of the horizontal axis is set by V_bc = 5.35 m³ and a = 2.49 m³. (The molecules rotate but do not oscillate.) During the transition,

(a) What is the change in internal energy of the gas, and

(b) How much energy is added to the gas as heat?

(c) How much heat is required if the gas goes from a to c along the indirect path albc?