You have been given the contract for making little conical cups that come with bottled water. These cups are to be made from a circular waxed paper of 4 inches in radius by removing a sector of length x (see Figure below).
By closing the remaining part of the circle, a conical cup is made. Your objective is to remove the sector so that the cup is of maximum volume.
Write a program that prompts the user to enter the radius of the circular waxed paper. The program should then output the length of the removed sector so that the resulting cup is of maximum volume. Calculate your answer to two decimal places.