As for the second part of the question, make sure you know the formula for volume. Once you have derived the definite integral, you should be able to see that the approach to solving the definite integral is similar to what I have uploaded here. The final answer that you should get for volume is 0.5п^3 units^3. Go try it out! If you are able to get the answer, it means you have fully understood my worked out solution in finding the area. All the best! :)