Please help with all parts a,b,c, and d. show how you get your answers. The pic is below

We create a cyclic process made of straight line changes in pressure and volume of an ideal gas (see a picture below). We start at point P1V1 and proceed counter-clockwise. Note that pressures all refer to external pressures. a) What is the change in total internal energy when we have completed the cycle'? b) What is the work performed on each leg of the cycle? c) What is the total heat evolved or absorbed. Does this 'engine' heat or oool or do nothing to the surroundings? d) What would be your answer to part c) if you traverse the cycle in a clockwise fashion